Act on this, mostly signal

Four months on a 262K-line Rust project without reading diffs

What to do

Try the CLAUDE.md budgets, CI size caps and decision logs described in the post.

Why

A solo developer replaced diff review with budgets, incident lessons, real-model test gates and mutation testing.

What the research found

A solo developer reports four months of Claude Code on a 262K-line Rust project with no diff reading, replaced by CLAUDE.md budgets, CI size caps, lessons-with-incidents, decision logs, real-model test gates and hand mutation testing. Self-reported and partly self-graded.

Claims and how well the evidence supports them

The repo has 262K lines of Rust, 788 merged PRs, 4,397 tests and 31 releases 98%
CLAUDE.md grew to 995 KB by August and was cut to a 30 KB router with a CI check capping it at 30,000 bytes 98%
Models used over four months were Opus 4.8 then Fable 5.1 and Opus 5.5 99%
Cost was a $100/month subscription plus about $114 of rented GPUs 99%

Evidence

reddit.com https://reddit.com/r/ClaudeAI/comments/1xay0jz/four_months_with_claude_code_on_a_262kline_rust
mindfork.io https://mindfork.io/articles/what-replaces-code-ownership/
github.com https://github.com/vshylov/mindfork-rs

Actionability rated medium.