Async or mildly complex thread stuff is like kryptonite for LLMs.
150k lines of vibe coded Elixir: The good, the bad and the ugly
21–30 of 91 posts
Re: 150k lines of vibe coded Elixir: The good, the bad and the ugly
#22"It writes 100% of our code"
- Silently closes the tab, and makes a remark to avoid given software at any cost.
Re: 150k lines of vibe coded Elixir: The good, the bad and the ugly
#23Everyone always ends these articles with “I expect it will get better”
What if it doesnt? What if LLMs just stay mostly the same level of usefulness they are now, but the costs continue to rise as subsidization wears off?
Is it still worth it? Maybe, but not worth abandoning having actual knowledge of what you’re doing.
Re: 150k lines of vibe coded Elixir: The good, the bad and the ugly
#24Everyone always ends these articles with “I expect it will get better” What if it doesnt? What if LLMs just stay mostly the same level of usefulness they are now, but the costs continue to rise as subsidization wears off? Is it still worth it? Maybe, but not worth abandoning having actual knowledge of what you’re doing.
I expect the costs at source will go down even if model performance doesn’t improve much, and hopefully that will offset the unraveling of subsidisation. I’d be happy enough with that outcome, I don’t really need them to be any better although of course it would be nice. I would love for them to be faster and cheaper.
Re: 150k lines of vibe coded Elixir: The good, the bad and the ugly
#25> In Elixir tests, each test runs in a database transaction that rolls back at the end. Tests run async without hitting each other. No test data persists. And it confuses Claude. This way of running tests is also what Rails does, and AFAIK Django too. Tests are isolated and can be run in random order. Actually, Rails randomizes the order so if the are tests that for any reason depend on the order of execution, they w…
Why not just write to the db? Just make every test independent, use uuids / random ids for ids.
Re: 150k lines of vibe coded Elixir: The good, the bad and the ugly
#26I can attest to everything. Using Tidewave MCP to give your agent access to the runtime via REPL is a superpower, especially with Elixir being functional. It's able to proactively debug and get runtime feedback on your modular code as it's being written. It can also access the DB via your ORM Ecto modules. It's a perfect fit and incredibly productive workflow.
Which models are you using? I’ve had mixed luck with GPT 5.2.
Opus 4.5 with Elixir has been remarkably good for me. I've been writing Elixir in production since ~2018 and it continues to amaze me at the quality of code it produces.
I've been tweaking my skills to avoid nested cases, better use of with/do to control flow, good contexts, etc.
Re: 150k lines of vibe coded Elixir: The good, the bad and the ugly
#27The imperative thing is so frustrating. Even the latest models still write elixir like a JS developer, checking nils, maybe_do_blah helper functions everywhere. 30 lines when 8 would do.
Re: 150k lines of vibe coded Elixir: The good, the bad and the ugly
#28> In Elixir tests, each test runs in a database transaction that rolls back at the end. Tests run async without hitting each other. No test data persists. And it confuses Claude. This way of running tests is also what Rails does, and AFAIK Django too. Tests are isolated and can be run in random order. Actually, Rails randomizes the order so if the are tests that for any reason depend on the order of execution, they w…
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Re: 150k lines of vibe coded Elixir: The good, the bad and the ugly
#29> In Elixir tests, each test runs in a database transaction that rolls back at the end. Tests run async without hitting each other. No test data persists. And it confuses Claude. This way of running tests is also what Rails does, and AFAIK Django too. Tests are isolated and can be run in random order. Actually, Rails randomizes the order so if the are tests that for any reason depend on the order of execution, they w…
Why not just write to the db? Just make every test independent, use uuids / random ids for ids.
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Re: 150k lines of vibe coded Elixir: The good, the bad and the ugly
#30The imperative thing is so frustrating. Even the latest models still write elixir like a JS developer, checking nils, maybe_do_blah helper functions everywhere. 30 lines when 8 would do.
Try these:
- https://github.com/agoodway/.claude/blob/main/skills/elixir-...
- https://github.com/agoodway/.claude/blob/main/agents/elixir-...
- https://github.com/agoodway/.claude/blob/main/agents/elixir-...
Getting pretty good results so far.