@alphabatcher: 540,000 lines of Rails is a brutal way to learn the agent era Garry's List shipped with: > 262,000 lines of app code > …

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Summary

A critique of large Rails codebases in the AI agent era, proposing a shift to skill-based development with agents, markdown skills, and TypeScript for deterministic I/O.

540,000 lines of Rails is a brutal way to learn the agent era Garry's List shipped with: > 262,000 lines of app code > 276,000 lines of tests > 127 background jobs > 33 cron jobs > a 1,778-line claim verifier Then GStack hit 105k GitHub stars Do not copy the Rails pattern 1. Finish the task with an agent 2. Say `skillify it` 3. Save the markdown skill 4. Keep TypeScript only for deterministic I/O 5. Add a unit test for the code 6. Add an LLM eval for the skill 7. Add an integration test across both 8. Add a resolver so the agent loads the skill next time A Rails feature serves one app A skill pack can run against the next hackathon, repo, customer inbox, research folder, or QA run Audit your repo this week Cut code that only exists to: > re-check model output > retry the same model call > validate what the model already has context for > schedule work because the agent has no reusable procedure > preserve a one-off prompt in chat history Keep the code that touches files, APIs, auth, billing, devices, databases Move the judgment into markdown Test the markdown Reuse the skill
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540,000 lines of Rails is a brutal way to learn the agent era

Garry’s List shipped with:

262,000 lines of app code 276,000 lines of tests 127 background jobs 33 cron jobs a 1,778-line claim verifier

Then GStack hit 105k GitHub stars

Do not copy the Rails pattern

  1. Finish the task with an agent
  2. Say skillify it
  3. Save the markdown skill
  4. Keep TypeScript only for deterministic I/O
  5. Add a unit test for the code
  6. Add an LLM eval for the skill
  7. Add an integration test across both
  8. Add a resolver so the agent loads the skill next time

A Rails feature serves one app

A skill pack can run against the next hackathon, repo, customer inbox, research folder, or QA run

Audit your repo this week

Cut code that only exists to:

re-check model output retry the same model call validate what the model already has context for schedule work because the agent has no reusable procedure preserve a one-off prompt in chat history

Keep the code that touches files, APIs, auth, billing, devices, databases

Move the judgment into markdown Test the markdown Reuse the skill

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