[dsiegel2275]

I'm only three weeks into using Claude Code but I'm now seeing impressive results using a structured, "role" or "persona" based approach in a large (500K+ SLOC) Elixir / Phoenix codebase. I'm using the $200 Max plan - so my inference costs are fixed.

For certain, the results are better when I use it to build new features into our platform - as opposed to making complicated refactors or other deep changes to existing parts of the system. But even in the latter case, if we have good technical documentation capturing the design and how parts of the system work (which we don't in many places), Claude Code can make good progress.

At first I was seeing a fair amount of what I would consider "bad code" - implementation and code that either didn't follow accepted coding style and patterns or that simply wasn't structured for reusability, maintainability. But after strengthening the CLAUDE.md file and adding an "elixir-code-reviewer" subagent which the "developer" persona had to use - the quality of code improved significantly.

Our platform is open source, you can see our current Claude commands and subagents here: https://github.com/Simon-Initiative/oli-torus/tree/master/.c...

[fny]

I didn't realize just how bad LLMs are with unpopular languages until now:

"Elixir lists do not support index based access via the access syntax"

"Never use else if or elseif in Elixir, always use cond or case for multiple conditionals."

[LiamPowell]

Interestingly I've found that Claude is very good at writing valid Ada, it just writes complete garbage that doesn't follow the specification at all. As an example I asked it to change the handling of command line arguments in a program so that duplicates would cause an error rather than being ignored. If I recall correctly it took 6 course corrections to get to what I asked for, but each time it wrote valid code that just didn't complete the task. One I remember was arbitrarily limiting the length of an argument to 4096 characters and then only accepting arguments that were exactly 4096 characters.

Here is the relevant change, it didn't have any sort of hidden complexity: https://github.com/Prunt3D/prunt/commit/b4d7f5e35be6017846b8...

[iandanforth]

Thanks for sharing that extensive documentation!