I replaced 1,000 lines of Python with a 500-word prompt

Short summary

Author replaced a 1,000-line Python agent service with a 500-word prompt running on a weekly Kubernetes CronJob, cutting costs from $0.70 to $0/run. Key patterns: two-lane classification (auto-fix vs. propose), agent self-defense gates (would a maintainer object?), and undo-first versioning. Economics reshape architecture — free re-runs beat clever state machines.

• •Replaced 1,000-line Python agent with 500-word prompt + 50-line shell script, dropping cost from $0.70 to $0/run
• •Three safety patterns: two-tier classification, self-defense gates, and undo-first versioning for low-risk autonomy
• •Prompt-as-code deployment pattern generalizes — same container, different prompt = new agent job

Generated with AI, which can make mistakes.