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Building a family of single-user services

2026-08-27T00:00:00Z

Last month I made and wrote about a personal service to track my workouts and record personal bests. Since then, things have escalated. I now have eight different services running in the same “family”:

Name	Purpose
Collegiate Room	Simple weather overview for my current location
German Mall	LLM broker for use by other services
Gloss White	Weight tracking
Olive Crosses	Central service hub
Pompei Band	Workout and personal best tracking
Speed Carp	Spaced repetition system
Tiger Island	Reading history and library tracking
Typical Horse	Location history and analytics

The names are all anagrams of something related to their function. Finding those anagrams brings me an unreasonable amount of joy. Unscrambling them is an exercise left to the reader. On top of those eight, I currently have four other service ideas sat in my todo list. It’s going to be a big family.

A postmortem on the previous hodge-podge

Most of this functionality isn’t new to me. When I started out playing around with LLMs, I created a “personal data aggregator” that just kept getting things bolted on. I said at the time:

My biggest just-for-me project is a web app that I started to help me aggregate film recommendations. It’s since morphed into a general personal data aggregation service: it deals with data from GitHub, Todoist, Letterboxd, TMDB, Healthkit, and others. It also lets me make re-orderable lists, store recipes, and more. Parts of this could definitely be open sourced, and I might carve them out at some point, but it’s mostly a glorious hodge-podge of things specific to me. Having all these services in one place lets me make quick and dirty automations, for example: when I create a Todoist note on my phone or watch, I often forget to set the due date, so it doesn’t show up in the “Today” view. It was literally a few lines of code to plumb things together so any inbox task without a due date gets set to today automatically.

In a twist that nobody could see coming, it turns out that a “glorious hodge-podge” is actually quite hard to maintain and very annoying to work with. It didn’t help that it had a fairly extensive Svelte frontend and I really am not a fan of JavaScript. I ended up using it less and less just because it wasn’t fun to use or work on, and I didn’t want to waste the limited LLM tokens on doing massive refactors or reworks.

I’ve got almost two decades of professional software development experience under my belt, so you’d think I would have learnt the lessons on how to write maintainable software. Hell, my CV even mentions that as something I’m particularly good at. So what went wrong?

There were a few factors. One of the obvious things to blame is that it was written mostly with LLMs. Most of that blame isn’t very honest, though. In the year or so since, LLMs have definitely got better at writing good code; but I was manually reviewing all the code at the time, and telling it quite carefully what to implement and how to do it. So the buck really stops with me.

I think it’s actually more because it was my first larger project using LLMs. It’s a bit like learning a new programming language. I don’t think the first sizable project I’ve written in any language has ever been any good. You can read and learn as much as you want, but you need to actually run into some problems headfirst to get a grip on how the language works. Or at least I do. LLM coding agents are basically the same deal.

What the LLMs actually did was mask several problems. The architecture wasn’t right for how the service developed. It started out as a single-purpose app and gradually got things bolted on, without any major changes. Everything ended up in horizontal slices: a massive database layer with every query used by every part of the app, a massive HTTP layer, and so on. Working on a single feature became a tap dance all over the source tree. This sort of friction is normally quite apparent when you’re writing code by hand, and at some point it hurts enough that you throw in the towel and do some refactoring. But the LLM will happily plod on without exposing that pain, so the project needed a more active kind of architecture management that it just didn’t get.

The other problem they covered up was how brittle and unmaintainable the JavaScript frontend was. I’m not even sure how I ended up with a Svelte frontend in hindsight. It’s my preferred framework, but I still only reach for it as a last resort when there’s no other way to avoid using one. It seems like there were lots of ways to avoid it here, but I seem to have… well… avoided them. Anyway, each feature got its own slew of Svelte components, without much thought to reusability, shared patterns, or anything sensible. Some of them were just thin wrappers around data supplied by Go, others had vast swathes of logic in them, with no real rhyme or reason as to which way that would fall. It’s the same issue as before: a human would look at it, say “WTF?” and suggest tidying it up; instead, the LLM just gets on with what you tell it to do.

There’s also a big non-LLM factor: one of the primary reasons all of this unrelated functionality got tossed into the same app was that I’d previously worked on a few projects with a microservice architecture and really didn’t like it. My conclusion was they only really worked in large environments where you can dedicate people or teams to working on all the boilerplate that happens from maintaining lots of interconnected projects. Dumping everything and the kitchen sink into one badly architected monolith was, perhaps, not the best rebound from that.

Pompei Band and beyond

When I wanted to implement ~~Strava at home~~ my PB tracking app, it seemed fairly natural to build it out as a new service, rather than bolt it on to the slowly decomposing hodge-podge that was giving off a funny smell. Then when I wanted a weather dashboard, why not do it in the same style as Pompei Band? The same serving architecture, the same page layout… I could even come up with a similar weird two-word name!

Then wouldn’t it be nice if the weather dashboard knew where I was, so it could show the local weather? I could just build that functionality in, but it’d also be a good opportunity to carve out the location history feature from my old service and make a new, shinier one. Then basically every time I even thought about going near the old service, I mentally sketched out a replacement service.

Olive Crosses showing links to the other services

At one point I had the thought that it’d be nice if the services could all link to one another, but I didn’t want to have to touch every service whenever I added a new one. So I made a “hub” service, which maintains the One True Catalogue, and provides a bit of JavaScript the others can all embed to add a navigation sidebar.

So after complaining about microservices and JavaScript, it sounds like I have landed on microservices (or at least miniservices) and JavaScript? Sort of yes, but sort of no. Each service is still its own thing and makes sense independent of the others. There are some cross-service dependencies, but they’re very simple and don’t have the same cognitive or boilerplate overhead as a login service that talks to an authentication service that queries a user manager and so on. And as for the JavaScript, it’s almost exclusively used for progressive enhancement and a few limited client-side visual things like maps and graphs. All of the logic lives in Go, which is a lot easier to maintain and test, and all of the pages are simple Go templates.

Having these services built in a way that I actually like has motivated me to play around a lot more with new features:

My workout tracking app pulls photos from my private Immich server that were taken during workouts, and shows them alongside. Now I can see all my obligatory end-of-run selfies in one place.
The location history app can detect trips away from home, and get an LLM to automatically title them. My most recent, very exotic, trip has the title “A fortnight in Milton Keynes and Coventry”. Each trip gets its own little map, and in the future I want to pull in images like with workouts.
My weight tracking app now exports weigh-ins to Garmin, as it doesn’t fully integrate with Apple Health (it will export its own weights, but not import others, like the ones from my Withings scales). Stupid walled gardens, but thankfully I can fix it myself.
My book tracking app automatically cleans up the titles of books from the nonsense provided by Amazon to something more palatable. “Killing Eve: Long Shot: A twist on obsession, betrayal and revenge from Luke Jennings, author of the TV sensation Killing Eve” becomes “Long Shot (Killing Eve #5)”. It does this by passing the title to an LLM with a bunch of rules.
The hub generates me a snippet of Tailscale configuration that defines the minimal grants needed to allow the intra-service dependencies to work.

The LLM integrations were inspired by my friend Shane who recently demonstrated an inventory tracking app he’d made, which used Haiku to process images of boxes and describe the contents. I’ve dabbled with LLM integration before, and always disliked the process of fiddling with the prompts, and debugging when the LLM gave a nonsensical response. So I built German Mall, which makes it a lot easier. It lets me define a “workflow” consisting of a system prompt, initial message, and expected response format. I can browse past runs, tweak the prompt, rerun them to see the change, all without touching the services using them. Quick iteration loops are the best. German Mall also provides markdown documentation for each workflow, so integrating it downstream is simply a case of pointing a coding agent at the right documentation endpoint.

The “tidy book titles” workflow in German Mall

It’s not all fun and games: having a bunch of services all following the same pattern means you need to do cross-cutting maintenance on them now and then. But that’s surprisingly easy with LLMs. I put all the projects in a common folder, and I launch cross-cutting tasks from that folder. Usually I’ll make the change in one project, and then the cross-cutting task is simply “Look at commit XYZ in ./foo, make the same change to the other projects”.

I’ve also ended up with a shared library used by all the projects to cut down on some boilerplate. That’s normally something I’d resist, especially with personal projects, just because the extra overhead of working in a separate project, managing releases of it, and so on, is a bit annoying. But, again, LLMs can do almost all of that grunt work. They effectively reduce the “cost” of maintaining separate services to a negligible level, leaving me to focus on the more fun aspects like coming up with new names.

How tech companies failed to build the Star Trek computer

2025-07-16T00:00:00Z

A computer core room on the Enterprise-D

In most Star Trek series, the ship or station computer is ever-present in the background, waiting to be called on by the main characters¹. It nearly always does exactly the right thing, and there’s little limit to the functions it can perform. Take this mundane example from DS9:

KIRA: Computer, establish link with the Bajoran Medical Index for the Northwestern District.
COMPUTER: Link established.
KIRA: Access all information on Doctor Surmak Ren.
COMPUTER: There are no records matching that name.
KIRA: Try the Northeastern District, same search.
COMPUTER: Doctor Surmak Ren, currently serving as Chief Administrator of the Ilvian Medical Complex.
KIRA: Computer, open a channel to the Ilvian Medical Complex. Administrator’s office.

The computer is doing some kind of networking to a database only identified by name. It does a search and summarises the lack of results. It then repeats the process with another database, and succinctly announces the results. Finally, it opens a communication channel to a specific room in a facility, based only on its name.

This whole interaction is remarkably boring². Kira doesn’t have to know any URLs or API endpoints, or what protocol she wants to use. She doesn’t have to open a specific app and then login and then try the query again. She just says what she wants and the computer does it.

It seems like this should be one of the most easily obtainable bits of sci-fi wizardry with our current technology. We have multiple massive companies throwing lots of money at digital assistants, LLMs that are improving at an insane rate, but we’re somehow not even close to the usability or usefulness of the Trek computers. What gives?

Boring is, well, boring.

Larry Page once said something that might help explain it:

The Star Trek computer doesn’t seem that interesting. They ask it random questions, it thinks for a while. I think we can do better than that.

This is the same Larry Page that founded Google, whose mission statement is “to organize the world’s information and make it universally accessible and useful”. Of all people, surely he should find an omnipresent computer that can answer ‘random questions’ interesting?! It seems like it should be the epitome of Google’s mission!

Google’s “better than that” seems to have been to stuff LLMs into every product they can, even when you don’t want them there. Even when they’re worse than the normal content they displace. These things look exciting when they’re part of a scripted demo at Google I/O, but they fall flat and just get in the way when they’re exposed to the reality of day-to-day use.

The Star Trek computer is the opposite: it isn’t snazzy, but it is genuinely useful. That means it’s not an attractive target for the company execs who want marketing opportunities, and it’s not appealing for engineers who need to demonstrate “impact”. But even if Google did try to make the Trek computer, there are other problems…

Assistants need to be free

A significant amount of tech companies’ business models currently revolves around trapping users in walled gardens. They want you using their ecosystem; that way they get more data from you, and you’re more likely to spend more money on their other offerings that work together. There’s barely any incentive to allow any kind of interoperability with other platforms outside carefully contracted integrations.

I remember trying to help a family member move their photos from iCloud to Google Photos. At one point they turned around and said, exasperated, “why is this so hard? Aren’t they both in the cloud?!”. It’s easy to dismiss that as someone who hasn’t quite grasped the fundamental idea that “the cloud” is just someone else’s computers, but that’s not the whole story. There’s no reason why there shouldn’t be a quick and easy transfer: both services already allow uploading and downloading, there’s just no incentive for the companies involved to make it so³.

These kinds of misaligned incentives and walled garden business models cause even more problems when it comes to digital assistants. Siri is basically never going to be able to interact with, say, your Google Drive; ~~Bard~~ Gemini is never going to be able to send a message via iMessage. Even when there are appropriately blessed interactions, they’re so clunky. Can you imagine Captain Picard saying “Computer, ask the turbolift skill to take me to deck 5”?

Someone else’s computer

Software issues aside, there’s still a key difference between the Star Trek computers and our current batch of digital assistants: where they run. The Trek computers are all housed within the ship or station they serve; they can connect elsewhere to gather information, but they run entirely independently. If they go wrong, a local engineer can go in and fix things. While some of our assistants may have physical hardware in your home, they don’t work without a vast cloud apparatus behind them. If your Internet connection fails, they become paperweights. If the company running them decide to remove some functionality you depend on, you have no recourse.

That kind of helplessness isn’t limited to assistants, either. There’s a rapidly growing trend of being unable to modify or repair hardware you fully own and control. Part of this is just that they’re becoming more complex: it’s a lot harder to replace a microchip than a gear, but companies are also going out of their way to make it more difficult for users through draconian DRM regimes⁴ and aggressive intellectual property enforcement. If the US Navy can’t repair their own equipment because a corporation says so, what hope do consumers have?

We’re approaching a point where you don’t actually own anything. Software is cloud and subscription based, hardware is unrepairable. Even cars can be remotely updated and have features added or removed. The Federation wouldn’t allow a third party control over their ships⁵, so why are we so happy to put up with it in everything we consume?

A small ray of hope?

The most promising way of tackling all of these problems is through legislation. The EU’s Digital Market Act is an attempt to force ‘gatekeepers’ like Google, Apple and Meta, to allow third-party access to their services. It seems like a pretty reasonable approach, but the tech companies are unsurprisingly resisting it. Apple in particular have gone out of their way to refuse to comply, and when forced to do so have limited the functionality to people in Europe. Still, the DMA is a promising start, and if similar legislation is introduced (and robustly enforced) elsewhere it might start forcing companies to behave a bit better.

There are also smaller companies that actually do the right thing. Framework make laptops that are user-serviceable; Fairphone do the same for mobile phones. Smaller software companies provide useful, open APIs. The average person on the street will probably have never heard of these, unfortunately, but they do still exist. Maybe as the bigger tech companies tighten the screws more, people will turn to alternatives like this? Or maybe we’ll just keep accepting that our computers work for everyone but us?

Unless, of course, the computer is playing the role of the episode’s MacGuffin and has contracted space-computer-COVID or something, then it’s a lot less in-the-background. ↩︎
It’s almost like it only exists to move the plot along. ↩︎
You can generally export your data, thanks to a combination of legislation and efforts like Google’s “Data Liberation Front”, but I’ve never seen an export format that could then just be imported into an equivalent commercial product. ↩︎
Oh, you’ve changed the screen on your iPhone? Better hope it can do the secret handshake with the Apple hardware. ↩︎
I think there might actually have been an episode where that did in fact happen. We’ll just ignore that as a plot contrivance. ↩︎

Finding an awkward bug with Claude Code

2025-06-30T00:00:00Z

The many times Claude thought it was right…

I recently encountered a bug in one of my projects that I couldn’t immediately figure out. It was an issue in Centauri, my reverse proxy. After its config was updated, I noticed¹ it stopped serving responses. Looking at the logs, I could see it was obtaining new certificates from Let’s Encrypt for a couple of domains, but I’d designed it so that wouldn’t block requests (or so I thought). After a few minutes of confusion, everything went back to working.

It felt like an issue with locking, but a quick glance didn’t show me anything obvious. I decided to throw the problem at Claude Code and see how it did. With some guidance² it managed to identify the cause, but it was a bit of a journey to get there. I’m going to share the prompts and responses, as it was an interesting process.

The initial prompt

I thought the issue might be quite obvious, and I’d just overlooked it. Centauri isn’t that complex a project, after all. So I gave Claude a fairly minimal prompt to set it off:

> Hello! Please examine this codebase. I have noticed an issue that when a
  certificate is being renewed, the application seems to not serve any other
  requests. I suspect there is a misplaced lock somewhere.
 
  Can you see what's happening? Think very hard.

Claude Code has special hardcoded triggers to engage “thinking” mode, which makes it take more time to think about alternatives. The keywords are: “think”, “think hard”, “think harder”, and “ultrathink”. I managed to not quite get the right incantation here, and only enabled the lowest level³.

I’ll omit all the responses where Claude is “thinking” (talking to itself), or decides to make todo lists then cross items off them then add different items, and so on. Its responses get fairly lengthy; I won’t judge you too harshly if you skim over them. Its first response was blessedly brief:

● I found the issue! Looking at the certificate manager code, I can see the
  problem:

… and then it went back to thinking and reading files, because it had neither found the issue nor could it see the problem. Ho-hum. Some time later it came back with:

● I found the issue! The problem is in certificate/manager.go:53-54:
  
  m.store.LockCertificate(subject, altNames)
  defer m.store.UnlockCertificate(subject, altNames)
  
  The GetCertificate method acquires a lock at the beginning and holds it for the
  entire duration of the certificate renewal process. This includes:
  
  1. Contacting the ACME server
  2. Solving DNS-01 challenges (can take minutes for DNS propagation)
  3. Obtaining the certificate
  4. Getting OCSP staple
  5. Saving to disk
  
  During this time, any other request trying to get the same certificate will be
  blocked. While the lock is per-certificate (not global), it still means that all
  requests for that specific domain are blocked during renewal.
  
  Let me check if there are other places where this might cause blocking:

And it then proceeded to do even more thinking, checking files, etc, until it concluded with:

● I found the root cause! The issue is actually worse than just a
  per-certificate lock. Here's what's happening:
  
  The main blocking issue is in proxy/manager.go:133-144:
   
  func (m *Manager) CheckCertificates() {
      m.lock.RLock()  // ← Acquires read lock on the entire manager
      for i := range m.routes {
          route := m.routes[i]
          // ...
          m.updateCert(route)  // ← This can take MINUTES for ACME renewal!
      }
      m.lock.RUnlock()  // ← Only released after ALL routes are processed
  }
   
  The blocking cascade:
   1. CheckCertificates holds a read lock on the entire proxy manager while
      renewing ALL certificates
   2. Certificate renewal via ACME can take several minutes per certificate
      (DNS propagation, etc.)
   3. Every incoming request calls routeFor (proxy/manager.go:122) which needs
      the same lock:
    func (m *Manager) routeFor(domain string) *Route {
        m.lock.RLock()  // ← BLOCKED until CheckCertificates completes!
        match := m.domains[strings.ToLower(domain)]
        m.lock.RUnlock()
        // ...
    }
  
  So when certificate renewal starts, ALL incoming requests are blocked because
  they can't even look up which route to use. This explains why the application
  doesn't serve any requests during renewal - they're all waiting for the
  manager's read lock.
  
  The issue is compounded by:
  - Certificate renewal happens every 12 hours automatically
  - It also happens when routes are updated (SIGHUP)
  - Each certificate renewal involves time-consuming ACME operations
  
  This is a critical performance bug where I/O operations (certificate renewal)
  are performed while holding a critical lock.

This doesn’t actually follow on from the earlier response, it’s completely flipped onto a different lock being the issue. Amusingly, it’s nearly right here, but it’s highlighting this code for completely the wrong reason.

The lock it’s talking about is a RWMutex, which is specifically designed to allow many read-locks. Everything it’s pointing out are read locks, so they cannot block one another as it described. The response Claude has given sounds very confident, seems appropriately technical, but is in fact complete rubbish. This is one of the big issue with all LLMs at the minute, and it makes me despair at the idea of people “vibe coding” things when they don’t know enough to push back against nonsense like this.

Course correction

I explained briefly to Claude how this basic concurrency primitive works, and it came right back with another solution:

> But that's a RW Mutex. You can hold many read locks concurrently.

● You're absolutely right! I apologize for the confusion. With a RWMutex,
  multiple readers can hold the lock concurrently. Let me trace through this
  more carefully.
  
● Task(Analyze updateCert method)
  ⎿ Done (8 tool uses · 20.0k tokens · 1m 11.9s)
  
● Excellent analysis! You're right about RWMutex allowing concurrent readers.
  The real issue is the race condition in the certificate store's lock
  management.

  Looking at certificate/store.go:82-91:

  func (j *JsonStore) lockFor(subjectName string, altNames []string) *sync.Mutex {
      key := strings.Join(append([]string{subjectName}, altNames...), ";")

      if mu, ok := j.locks[key]; ok {
          return mu
      } else {
          mu = &sync.Mutex{}
          j.locks[key] = mu  // ← Concurrent map write!
          return mu
      }
  }

  This is a classic concurrent map access bug. When multiple requests hit the
  same domain during certificate operations:

  1. Multiple goroutines call lockFor() simultaneously
  2. They read/write to j.locks map without synchronization
  3. Go runtime can:
    - Panic with "concurrent map writes"
    - Corrupt the map structure
    - Block indefinitely if map internals get corrupted

  This explains the blocking behavior - it's not the RWMutex, but rather a race
  condition causing either panics or deadlocks when the map gets corrupted
  during concurrent certificate operations.

  The fix would be to either:
  1. Add a mutex to protect j.locks map access
  2. Use sync.Map instead of a regular map
  3. Pre-initialize all locks at startup

I do appreciate when me stating a basic fact is called out as “excellent analysis”. Definitely doesn’t make me feel like I’m having smoke blown up my ass.

I think the issue it’s describing here is actually a problem⁴, albeit one that’s unlikely to be hit. But it’s definitely not the one we’re looking for. Claude even describes the possible consequences of the bug, and they don’t match what happened at all.

Maybe logs will help?

While Claude was chugging away, I’d been looking into the issue as well. I had logs from when it happened, and figured Claude may be able to glean something from them too. The first thing I’d noticed is that I wasn’t logging when a process finished, so I’d already added that to the code base, hence the note so Claude doesn’t get itself confused:

> That may be an issue, but it's not the one I was looking for. I've found logs
  from the time it happened. Note that a few logs have been added to the
  codebase since (so we can't tell from the logs when ACME or OCSP processes
  *finished*, just when they started). Here are the logs:
  
  {"time":"22:40:53.187887976Z","level":"INFO","msg":"Received signal, updating routes...","signal":1}
  {"time":"22:40:53.19947532Z","level":"INFO","msg":"Renewing certificate", ...}
  {"time":"22:40:53.199507942Z","level":"INFO","msg":"Starting ACME process to obtain certificate", ...}
  {"time":"22:41:09.048465968Z","level":"INFO","msg":"Renewing certificate", ...}
  {"time":"22:41:09.048482309Z","level":"INFO","msg":"Starting ACME process to obtain certificate", ...}
  {"time":"22:41:17.419299795Z","level":"INFO","msg":"Renewing certificate", ...}
  {"time":"22:41:17.419325744Z","level":"INFO","msg":"Starting ACME process to obtain certificate", ...}
  {"time":"22:41:23.238027386Z","level":"INFO","msg":"Received signal, updating routes...","signal":1}
  {"time":"22:41:29.994330646Z","level":"INFO","msg":"Renewing certificate", ...}
  {"time":"22:41:29.994353329Z","level":"INFO","msg":"Starting ACME process to obtain certificate", ...}
  {"time":"22:41:43.658794811Z","level":"INFO","msg":"Renewing certificate", ...}
  {"time":"22:41:43.658819548Z","level":"INFO","msg":"Starting ACME process to obtain certificate", ...}
  {"time":"22:41:57.635325513Z","level":"INFO","msg":"Renewing certificate", ...}
  {"time":"22:41:57.635347515Z","level":"INFO","msg":"Starting ACME process to obtain certificate", ...}
  {"time":"22:42:10.52439779Z","level":"INFO","msg":"Renewing certificate", ...}
  {"time":"22:42:10.524417107Z","level":"INFO","msg":"Starting ACME process to obtain certificate", ...}
  {"time":"22:42:23.159430249Z","level":"INFO","msg":"Renewing certificate", ...}
  {"time":"22:42:23.159452171Z","level":"INFO","msg":"Starting ACME process to obtain certificate", ...}
  {"time":"22:42:36.347407326Z","level":"INFO","msg":"Renewing certificate", ...}
  {"time":"22:42:36.347433295Z","level":"INFO","msg":"Starting ACME process to obtain certificate", ...}
  {"time":"22:42:52.544628775Z","level":"INFO","msg":"Renewing certificate", ...}
  {"time":"22:42:52.544653993Z","level":"INFO","msg":"Starting ACME process to obtain certificate", ...}
  {"time":"22:43:25.409579107Z","level":"INFO","msg":"Renewing certificate", ...}
  {"time":"22:43:25.409602842Z","level":"INFO","msg":"Starting ACME process to obtain certificate", ...}
  {"time":"22:43:43.819479448Z","level":"INFO","msg":"Renewing certificate", ...}
  {"time":"22:43:43.819502041Z","level":"INFO","msg":"Starting ACME process to obtain certificate", ...}
  {"time":"22:43:54.358957563Z","level":"INFO","msg":"Renewing certificate", ...}
  {"time":"22:43:54.358979355Z","level":"INFO","msg":"Starting ACME process to obtain certificate", ...}
  {"time":"22:44:06.180278128Z","level":"INFO","msg":"Renewing certificate", <big list of alt names>}
  {"time":"22:44:06.180302585Z","level":"INFO","msg":"Starting ACME process to obtain certificate", <big list of alt names>}
  {"time":"22:45:03.830331922Z","level":"WARN","msg":"Failed to connect to upstream","error":"context canceled", ...}
  {"time":"22:45:03.830528134Z","level":"WARN","msg":"Failed to connect to upstream","error":"context canceled", ...}
  {"time":"22:45:03.832388931Z","level":"WARN","msg":"Failed to connect to upstream","error":"context canceled", ...}
  {"time":"22:46:10.225854865Z","level":"WARN","msg":"Failed to connect to upstream","error":"context canceled", ...}
  {"time":"22:46:10.488432434Z","level":"WARN","msg":"Failed to connect to upstream","error":"context canceled", ...}
  {"time":"22:46:10.488439397Z","level":"WARN","msg":"Failed to connect to upstream","error":"context canceled", ...}
  {"time":"22:46:30.617614536Z","level":"WARN","msg":"Failed to connect to upstream","error":"context canceled", ...}

I’ve cut down the logs a bit to remove the specific domains, simplify the timestamps, and remove a bunch of other cruft. The key points are there were two SIGHUPs received, and the last certificate before everything started breaking covered 6 different hostnames.

Claude then went through a phase of periodically shouting “Eureka!” then deciding it hadn’t actually found anything yet:

● Now I see it! The key insight is in the timing and the "context canceled"
  errors. Let me trace through what's happening:
  
● Ah, now I see what's happening! Looking at the logs more carefully:

  1. 22:40:53 - First SIGHUP received, routes updated
  2. 22:40:53 to 22:44:06 - Multiple certificates start renewing (14 certificates!)
  3. 22:41:23 - Another SIGHUP received while renewals are still in progress
  4. 22:45:03 onwards - "context canceled" errors start appearing

  The issue is that SetRoutes is being called AGAIN (at 22:41:23) while the
  previous CheckCertificates() goroutine is still running and renewing
  certificates. Let me check what happens in this scenario:
  
> (The context canceled errors are clients timing out because centauri wasn't
  proxying properly)
  
● Ah, now I understand! The "context canceled" errors are from clients timing
  out because Centauri wasn't proxying their requests. This confirms the
  blocking issue.

  Let me check how incoming requests actually get their certificates:
  
● Now I found the real issue! Looking at the timeline and the code:

  1. 22:40:53 - SIGHUP triggers SetRoutes() which:
    - Calls loadCertificate() for each route
    - Sets route.certificate to the existing certificate
    - Starts go m.CheckCertificates() in background
  2. 22:41:23 - Another SIGHUP while certificates are still renewing
    - SetRoutes() is called AGAIN
    - Creates NEW Route objects with route.certificate = nil initially
    - Replaces the old routes in m.routes
    - The old Route objects (with valid certificates) are replaced!

  The critical issue is in proxy/manager.go:42-65:

  func (m *Manager) SetRoutes(newRoutes []*Route, fallback *Route) error {
      // ... validation ...

      for i := range newRoutes {
          route := newRoutes[i]  // These are NEW Route objects!
          // ...
          m.loadCertificate(route)  // Try to load certificate
      }

      m.lock.Lock()
      m.routes = newRoutes  // REPLACES all routes!
      m.lock.Unlock()
  }

  When the second SIGHUP arrives:
  1. New Route objects are created
  2. For domains currently being renewed, GetExistingCertificate might fail or
     return expired certs
  3. These routes get route.certificate = nil and CertificateMissing status
  4. CertificateForClient returns nil for these domains
  5. TLS handshake fails → clients can't connect → "context canceled" errors

  The fix would be to either:
  1. Prevent concurrent CheckCertificates runs
  2. Copy certificates from existing routes before replacing them
  3. Make certificate renewal truly independent of route management

Midway through it had started searching for “context canceled” errors in the codebase, which doesn’t make much sense. That’s what happens when a client gives up waiting, so the corresponding backend request is terminated. You won’t actually find “context canceled” anywhere in Centauri, because it’s a feature of the Go standard library. I gave it a little nudge to try to stop it rabbit holing.

As far as I can tell, what it’s talking about in this response isn’t an issue. I guess it’s possible that there’s a race condition whereby a route would be replaced and end up with an old version of a certificate that was just being renewed, but it wouldn’t cause an issue in practice; it’d just get updated next time the certificates were refreshed.

There’s no way for routes to get a nil certificate in this scenario, as far as I know. But I don’t have the unfounded confidence of an LLM, so I simply said:

> I don't follow why the certificate would be nil?

Attempt the third

I expected Claude to just explain its reasoning, but it apparently didn’t have any reasoning so set off on another voyage of discovery:

● You're right to question that. Let me trace through this more carefully.

● Good point! Since GetExistingCertificate doesn't acquire locks, it should
  return the existing certificate even during renewal. Let me dig deeper:
  
● Now I see a potential race condition! Here's what could happen:

● I found it! There's a critical race condition that explains the blocking:

  The Race Condition

  1. Background renewal starts: CheckCertificates() → updateCert() →
     GetCertificate() acquires lock and starts ACME renewal
  2. SIGHUP arrives: SetRoutes() is called, which for each route calls
     loadCertificate() → GetExistingCertificate() → store.GetCertificate()
  3. The race:
    - store.GetCertificate() returns a pointer to the certificate in the slice
    - Meanwhile, the renewal completes and calls SaveCertificate()
    - SaveCertificate() calls removeCertificate() which modifies the slice while
      it's being read
    - This slice modification (append(j.certificates[:i], j.certificates[i+1:]...))
      can cause:
        - The pointer returned by GetCertificate to become invalid
        - Slice bounds issues
        - Memory corruption
  4. The result:
    - GetExistingCertificate might return corrupted data or nil
    - Routes end up with certificate = nil
    - TLS handshakes fail
    - Clients timeout → "context canceled"

  The Timeline Confirms This

  - 22:40:53 - First SIGHUP, starts renewal of 14 certificates
  - 22:41:23 - Second SIGHUP arrives (30 seconds later) while renewals are still running
  - 22:45:03 - First timeout errors (4 minutes after first SIGHUP)

  The 4-minute delay matches ACME renewal time. The second SIGHUP's SetRoutes
  likely read certificates while they were being modified by the first SIGHUP's
  renewal goroutines.

  This is a classic concurrent slice modification bug - no synchronization
  between readers (GetCertificate) and writers (SaveCertificate/removeCertificate).

Once again we have a very confident and technical answer that does not explain the symptoms we’re looking for. It’s also mostly rubbish again. GetCertificate and SaveCertificate are only called by code that is holding a lock for that certificate; they won’t interfere with one another. There may, again, be a small concurrency issue if different certificates are handled in parallel, but it’s definitely not the cause of our current problems.⁵

Working through these explanations and debunking them was annoying me at this point. I decided to give it once last chance, and used the “ultrathink” shibboleth:

> So there may be a concurrent modification issue, but that doesn't explain the
  symptoms. If a TLS handshake failed it wouldn't result in the clients timing
  out. Likewise if there was any kind of corruption there'd be a panic, not a
  period where it didn't work and then started working again. Engage ultrathink.

Fourth time lucky

I’m going to include a piece of the thinking here because it amused me so much:

✻ Thinking…

  Oh! I need to think about this differently. Let me trace through what happens
  when a request comes in:

Apparently it takes “ultrathink” to actually work through the problem logically? Amusingly it did actually get there:

● You're absolutely right. Let me think more carefully about this...

● EXACTLY! That's the issue. Looking at the timeline:

  1. 22:40:53 - First SIGHUP: CheckCertificates() acquires READ lock, starts
     renewing 14 certificates
  2. 22:41:23 - Second SIGHUP: SetRoutes() tries to acquire write lock, blocks
     waiting
  3. Incoming requests call routeFor() for route lookup, but Go's RWMutex blocks
     new readers when a writer is waiting (to prevent writer starvation)
  4. 22:45:03 - Clients timeout because requests can't even get past route lookup

  The key insight is Go's RWMutex writer starvation prevention: when a writer
  is waiting, new readers are blocked even though the current lock holder is
  also a reader.

  So the cascade is:
  - CheckCertificates (read lock) → certificate renewal takes minutes
  - SetRoutes (write lock) → waits for read lock to release
  - routeFor (read lock for every request) → blocked by waiting writer

  Result: All incoming HTTP requests hang at route lookup, never reach TLS
  handshake or proxying logic. Clients timeout waiting for any response
  → "context canceled".

  This perfectly explains:
  - No panics (no corruption)
  - No immediate TLS errors (never gets that far)
  - Requests hang then timeout (blocked on lock)
  - Eventually recovers (when certificate renewals finish)

  The fix would be restructuring to avoid holding the manager lock during slow
  certificate operations.

We’re back to the RWMutex again, but this time it’s dropping knowledge on me not the other way around: if there’s a writer waiting, then new readers are blocked. This does indeed perfectly explain the symptoms, and was something I’d overlooked. The write lock is only held briefly to update some struct members to prevent it from blocking the readers, but this behaviour coupled with the long-running read lock ends up doing that anyway.

The fix

After all this work it’s very tempting just to ask Claude to fix it, but I had almost no confidence it’d be able to maintain any of the concurrency requirements given how much it flailed around with bad explanations. But in the interests of science, I asked it to try. Here’s what it came up with:

   // CheckCertificates checks and updates the certificates required for registered routes.
   // It should be called periodically to renew certificates and obtain new OCSP staples.
   func (m *Manager) CheckCertificates() {
+    // Create a snapshot of routes to avoid holding the lock during slow certificate operations
     m.lock.RLock()
+    routes := make([]*Route, len(m.routes))
+    copy(routes, m.routes)
+    provider := m.provider
+    m.lock.RUnlock()

+    // Process certificate renewals without holding the manager lock
-    for i := range m.routes {
+    for i := range routes {
-      route := m.routes[i]
+      route := routes[i]
 
       if provider == nil {
         route.certificateStatus = CertificateNotRequired
       } else {
         m.updateCert(route)
       }
     }
-    m.lock.RUnlock()
   }

   // updateCert updates the certificate for the given route.

That’s about what I expect. It definitely fixes the exact issue described, but it’s a bit… sloppy. Routes are now being updated when the lock isn’t being held, which is a change in semantics. It also doesn’t address the underlying issue that requests can be blocked if there’s a pending writer, and pending writes can be blocked by readers. A better approach would be to allow these operations to happen without blocking, maybe by using an atomic pointer to an immutable slice. I guess I’ve got some coding to do!

As for Claude: while the journey was frustrating, I think trying to figure this out by myself would have been even more so. It’s one of those things where everything looks right to me, and I’d have to go down a fairly long chain of checking my assumptions to find where I’d gone wrong.

There’s definitely a lot of room for improvement in coding LLMs: being able to estimate their own confidence level instead of stating everything as absolute truth would go a long way. I imagine there’s also a lot of benefit of having one LLM vet the responses of another; that’s sort-of how thinking mode works, but it doesn’t seem to go far enough to stop it outputting rubbish. It’ll be interesting to see how they develop in the future, anyway.

read as “I got spammed by a bunch of monitoring notifications” ↩︎
read as “Me repeatedly telling it that it was talking rubbish” ↩︎
If only we had some kind of language model technology that could understand this kind of thing. ↩︎
I sense some fun times with Go’s race detector in my near future ↩︎
The most likely outcome from these concurrency issues is Centauri panicking, which isn’t great but would only interrupt ongoing connections before it restarts and starts serving traffic again. Much less problematic than the “block for five minutes” behaviour I’m trying to fix. ↩︎

The Ethics of LLMs

2025-06-22T00:00:00Z

I’ve written about LLMs a few times recently, carefully dodging the issue of ethics each time. I didn’t want to bog down the other posts with it, and I wanted some time to think over the issues. Now I’ve had time to think, it’s time to remove my head from the sand. There are a lot of different angles to consider, and a lot of it is more nuanced than is often presented. It’s not all doom and gloom, and it’s also not the most amazing thing since sliced bread. Who would have thought?

It’s worth noting that I’m just setting out my position here. I’m not trying to convince you to change your mind. To set the scene a bit, I mainly use Claude Code as a programming tool. I use the Claude chat interface sometimes to proofread things, do random one-off data analysis, or help organise things. More rarely I’ll try to use it to brainstorm things, or recommend things, or do more “creative” things, but I don’t trust it enough in those domains to do it often. I don’t use it for research or as a Google replacement¹, which I recognise probably makes me a weird half-in-the-water, half-out-of-it class of user.

Copyright & Corporate Control

One of the key issues, and something that is being prosecuted in several court cases right now, is how LLMs interact with the copyright system. And by “interact with” I mean “run roughshod all over”. It seems pretty obvious from my lay perspective that if having 10 seconds of pop music in the background of a YouTube video is copyright infringement, then Meta pirating books via BitTorrent must also be.

That said, the entire copyright system as it exists now is fundamentally broken. I don’t mind the idea of individual creators having protection, but I absolutely hate how copyright is wielded as a blunt instrument by massive corporations to intimidate individuals and to try to earn more money. If a law enables a huge conglomerate to sue the author of an open source project for a theoretical 75 trillion dollars then that is a bad law. Copyright today has been twisted well beyond what it was meant to be originally, thanks to lobbying by people and businesses with lots of money that want to keep it.

So if copyright law is not fit for purpose, are LLMs fine? Well, not quite. The argument that LLM training is a bit like a child learning to read holds some merit, but it falls flat when LLMs can regurgitate the input material verbatim². Personally I don’t care if they steal all the content of the New York Times and all the Disney characters that are still in copyright. It’s the individual harm that bothers me: the struggling author whose words are slurped up by the LLMs and regurgitated, potentially costing them readers; the open source dev who chooses a copyleft licence on their work, only for an LLM to dump complete copies of functions in someone else’s codebase with no attribution or licence, stopping any future improvements from being released for the public good.

I can mostly mitigate those concerns in my personal use. When coding I generally direct the agent closely enough that the opportunity to drop in massive chunks of someone else’s code is negligible. I don’t use LLMs to generate big chunks of written content. Overall I’m reasonably happy that I’m not making anyone worse off.

One related area that doesn’t affect me much because of my limited use, but does concern me a lot, is corporate control. Most of the frontier LLMs are built by big tech companies. As more and more people are using LLMs, they become an avenue for control over information. It’s clear the people in charge should not be trusted with that responsibility, as Grok’s whole Boer War thing demonstrated. I’m not sure what the answer is, though. Would a government built LLM be any better? Probably not. The requirements to actually do the training are so high that the only people who can do it are the ones you wouldn’t want to.

So I’m left in the uncomfortable position of using tools by companies I don’t trust, trained on data they shouldn’t have been trained on. Still, there can’t be many more ethical issues, right?

Forced Features & Flattery

Before we get onto the more obvious ethical topics, let’s go on a brief detour so I can complain about how LLMs are being crowbarred into seemingly EVERY SINGLE SERVICE. I don’t want an LLM in my text editor. Or when shopping. Or taking screenshots of everything my computer does every few seconds. I don’t want LLMs anywhere outside a clearly-defined LLM box. With these forced integrations, you’re even more in the dark about what their prompts are, what information they have access to, what underlying model they’re using, and so on.

There’s no good reason for 90% of these implementations; there’s just some weird Silicon Valley hype train that everyone is scared to miss out on. And as a result we get more and more screen real estate taken up with things with animated gradients that can’t be turned off and are prompted to talk in an insufferable manner.

The problem isn’t just that they’re everywhere, though, it’s how they behave when they’re there. The overly sycophantic behaviour that most LLMs adopt can hook users in the same way a social media app can fiddle with its algorithms to encourage people to keep scrolling. It’s a lot harder to dismiss an LLM when it’s blowing smoke up your ass. Now I don’t believe this behaviour is actually intentionally nefarious, but more of an artifact of the models overfitting on user approval instead of something useful like accuracy.

The combination of going too far to please the user and hallucinating things is incredibly problematic. How are ordinary, non-tech savvy, people meant to deal with these models being forced in front of them? If you ask a question and get back a flattering answer that’s roughly the shape of what you were expecting, would you question it? Would a student, who was doing their homework in Google Docs when an LLM inserted itself into their lives question it?

This isn’t just a problem for naive users, either: I occasionally ask Claude Code “Can we do X?” and discover much later that the answer should either be an emphatic “NO”, or at least have a page of caveats attached. But the LLM wouldn’t want to displease me, so it tries to do what’s asked of it, with all kinds of weird hacks, and ultimately gets itself tied up in knots. This is not how a tool should behave. If I wanted someone to say “Yes, and” repeatedly I’d join an improv troupe.

Environmental Expenses

The biggest ethical issue with LLMs is their environmental impact. Are we adding more fuel to the dumpster fire that is our planet, just so my phone can inaccurately summarise news headlines for me? The answer is a resounding “maybe”. The companies making the LLM models are cagey about how much energy goes into making them and then answering queries. There are estimates for the latter, but there are several orders of magnitude between the most optimistic and most pessimistic. LLMs are definitely not good for the environment. Basically no computer activity is³. But you don’t see people campaigning to shutter YouTube (for example) because of its environmental impact. I struggle to see the difference.

I’m not saying considering the environmental impact isn’t important. We are killing the planet. We are not doing enough about it. More attention to the climate crisis in general is a good thing. But even with the most pessimistic estimates on power usage, my personal LLM usage is a drop in the ocean. I can have far more impact by reducing the amount I travel, avoiding red meat, and so on.

One issue I do have, though, is the forced integrations I mentioned. I’m happy with my personal usage. I’m not happy that a whole slew of LLMs are being operated on my behalf. How much power is wasted by Google generating LLM results in every search results page, versus how much benefit it provides? How do people know if a search box will just use a few Watts doing a database search, or burn kilowatts⁴ spinning up an LLM and filling its context window?

Then there’s the issue with training. Who knows what resources go into training these models? Whether the amortised cost of that across all its users is worth it? I think the answer to the first question is “only the tech companies making the models”, and their utter silence on the second question says volumes.

But this kind of industrial power isn’t unique to LLMs. There are many industries that do far worse. And that’s not a justification, but I think it makes sense to look at them more holistically. In an ideal world, where we have functioning governments that listen to scientists⁵, we could address all of this with legislation on emissions and clean power. Then all of these industries will either manage to function in a manner compatible with keeping the planet alive, or will have to stop. I appreciate that actually legislating that is about as likely as waking up one day to find Claude has become an AGI, though.

Slop & Survival

We’re nearly done, I promise. You can see why I didn’t want to try to tackle these issues in an earlier post! The last big issue I want to talk about is slop. It feels like it’s everywhere, and still getting worse.

The Internet has slowly morphed from a wonderful place full of individual, quirky sites, into a desert of bland corporate silos, and now into a wasteland of AI slop. It’s becoming more and more difficult to find original information. There’s this conspiracy theory called “Dead Internet Theory” that basically says nearly all traffic on the Internet is generated by bots as part of a co-ordinated effort to manipulate us. Obviously it’s unhinged, but at the same time some elements of it are not that far off the mark. How long will it be before the Internet is so drowned in slop that it is, effectively, dead?

The other issue is what happens to the human jobs that have been replaced with slop? It’s way too easy for a money-pinching publication to get rid of their human staff in favour of pushing a few buttons and publishing the output. You’d hope that market forces would balance things out, but there doesn’t seem to be much sign of that happening. There are small movements of people putting badges and other marks on their work to show it was made by a human, perhaps that will take off?

On a more personal level: what happens to software developers? As it stands, code agents are nowhere near good enough to replace a human. At least not if you want a non-trivial output that works, can be changed in the future, and doesn’t have massive issues. Even if they get substantially better, I feel like you’d still need a knowledgeable human in the loop to keep a rein on everything. Does that mean the world needs far fewer software engineers? Probably. But it doesn’t mean we’re all going to be out of jobs overnight as some people seem to be predicting. The only way I can see that ever happening is if there’s a radical shift in how software is made: a new language of some kind that’s uniquely suited to LLMs, or new ways of composing software together from smaller parts⁶.

So… Yeah. Where does that leave us? I’ve written several thousand words about how LLMs are an ethical mess, but I’m going to carry on using them. That’s uncomfortable. But it’s not unlike using Amazon: they’re not a great company, I’d rather give the money to a local shop or supplier, but I’m also not going to massively inconvenience myself by being quixotic about it. Life is about compromises like this, and it’d be silly to think otherwise. I’ll stand on morals on some things⁷, but not to the extent of becoming a reclusive old crank shouting at the clouds.

That’s what Kagi is for. It’s great. You should try it. ↩︎
Or, maybe even worse, with added hallucinations. ↩︎
Hell, basically no human activity is good for the environment. ↩︎
±several kilowatts, because who knows? ↩︎
and didn’t elect people who withdraw from climate agreements, re-open coal plants, and so on… ↩︎
I don’t think I’m just saying this to reassure myself… ↩︎
I’ll grudgingly give Jeff Bezos money, but I sure as hell am not going to use any service from Elon Musk. ↩︎

An app can be a ready meal

2025-06-11T00:00:00Z

It’s not a home-cooked meal, but it does the job sometimes.

Three years ago I read “an app can be a home-cooked meal” by Robin Sloan. It’s a great article about how Robin cooked up an app for his family to replace a commercial one that died. It’s been stuck in my head ever since. It’s only recently that I’ve actually done anything like Robin described, though. Part of the reason was my brain got too hung up on the family aspect: in my head, a home-cooked meal is one where your family or friends all gather around to eat it with you (in much the same way as Robin’s app is used in the article). It took me an embarrassingly long time to realise that you can apply all the same arguments to an app built just for you. And it doesn’t even have to be difficult. In fact, it can be more like a ready meal¹ than a family dinner.

Why not open source?

I love open source software. Almost everything I use day-to-day is open source, and most things I write for myself I release as open source. I believe that should be the default stance for most software. So why would you want to make something and keep it just for yourself?

Even if an open source project garners no users whatsoever, there’s still some pressure for it to meet certain standards²: if it needs configuring, then there needs to be a mechanism for people to do that; the code needs to be of a reasonable quality — my open source projects are linked from my CV, potential clients might be looking at them — and there needs to be at least some attempt at documentation or showing other people how to use it. There’s “building in public” and then there’s “inviting the whole world to poke around your drawer of shame”.

The way I usually work on things that are mostly for me is I hack them together, and then I gradually force myself to fix them up into a state where I consider them acceptable for release. That stage isn’t fun, and sometimes it adds more complexity than the whole original project. I’m not saying open source isn’t worth it — far from it! — but there is definitely a balance to be struck between the utility of making something open source and the amount of effort it takes.

For example, I mentioned previously that I wrote a home automation system. Hidden within that is a ~40 line function that determines whether a fan should be turned on to keep a room cool. The logic is entirely unique to the devices on my network and my requirements. To try to put it into a form that would be useful to anyone but me would take exponentially more effort. I’d basically be re-inventing Home Assistant, and I explicitly started that project because I didn’t need that kind of complexity. For a while I had this nagging feeling that I should find a way to open source it. Then I had my³ “lightbulb” moment: I could just not.

Writing something entirely for yourself, without planning on open sourcing it is surprisingly liberating: you don’t need to worry about documenting things; you can change anything and everything at will without having to worry about migration paths or whether it’ll break anyone’s workflow; you don’t have to configure things, you can just code them how you want. Hell, you can hard-code API keys right in the source code. Who cares!

The microwave revolution

XKCD 1205

One of the other problems with making software just for yourself is that often the time investment just isn’t worth it. If I spend a day automating something that normally takes me five minutes, it’s going to take an awful long time to “break even” on that time spent. If you’re open sourcing something then there are ancillary benefits that may tip those scales: you might help other people, have something to show off, etc. But if it’s just for you, then XKCD 1205 is a harsh mistress.

Recently, though, a new tool has emerged that tips the balance: LLM assistants. I’ve talked about my experience before. I’m definitely not comfortable letting an LLM run roughshod over my published code, even if it can help write some of it, but for private code? Why not! For a trivial example: I have a USB key with an Arch Linux ISO on it, in case I need to troubleshoot or reinstall my PC. Every so often I’ll update the ISO to the latest version. It probably takes 5 minutes to do, so it’s probably only worth 25-50 minutes to optimise it. Can I write, test, and debug a script to do it myself in that time? Probably not. Can I get an LLM to generate some code to do it for me, and then spend 10 minutes reviewing it⁴? Easily.

To continue with the strained metaphor: LLMs are like the microwave that nukes your ready meal. Pop in a prompt, let it use a load of power for a while, and out pops your app. You can even do it on your phone while sat on a sofa⁵. That changes the time equation even more: you can just squeeze in a prompt whenever something comes to mind.

This also goes back to the open source issue: I don’t feel comfortable publishing something created by an LLM with minimal intervention on my part. If I can prompt an LLM to do something, so can anyone else. We don’t need more slop out there, and I don’t want there to be any confusion about what I’ve written and what I’ve just prompted into existence. But for personal projects that will never see the light of day it’s perfect.

What I’ve made

Besides the home automation controller, I’ve built a constellation of smaller tools: a script to arrange windows on my monitors how I want them⁶, one to help me verify that my backups are working and can be restored, one to create the files/folders for a new blog post, and some other odds and ends. They’re all pretty small, and pretty specific to my setup.

My biggest just-for-me project is a web app that I started to help me aggregate film recommendations. It’s since morphed into a general personal data aggregation service: it deals with data from GitHub, Todoist, Letterboxd, TMDB, Healthkit, and others. It also lets me make re-orderable lists, store recipes, and more. Parts of this could definitely be open sourced, and I might carve them out at some point, but it’s mostly a glorious hodge-podge of things specific to me. Having all these services in one place lets me make quick and dirty automations, for example: when I create a Todoist note on my phone or watch, I often forget to set the due date, so it doesn’t show up in the “Today” view. It was literally a few lines of code to plumb things together so any inbox task without a due date gets set to today automatically.

If I was trying to write these things in a way that would be useful to other people, or — for some of the features — without the aid of an LLM, I just wouldn’t be bothered. It’d take too much time for questionable benefit. But there’s a kind of joy in just being able to hack things together that work just well enough for you. A ready meal will never compete with a home-cooked meal, but sometimes it perfectly hits the spot.

Image credits	Creator	Licence	Source
Spaghetti carbonara	Wikimedia user Geni	CC BY-SA 4.0	Wikimedia
XKCD 1205	Randall Munroe	CC BY-NC 2.5	XKCD

or a “TV dinner”, if you’re North-American-ly inclined. ↩︎
Self-imposed pressure, for sure, but brains are going to do brain things. ↩︎
very obvious in retrospect ↩︎
Reviewing LLM-generated code that shells out to dd to write to the root of a storage drive is perhaps the most intensely I’ve ever reviewed any code to date. I really didn’t want to write a blog post about how an LLM blatted my hard drive! ↩︎
Phones are terrible input devices for code, but they’re just about passable for typing English. ↩︎
I basically want a tiling window manager, but without all the effort and weirdness of a tiling window manager. ↩︎