$ ls ./blog # notes and case studies

Writing

Notes and case studies from building production systems. What was tried, what cost, and what changed.

• 2026-10-05 Note
  Draining, not stopping

  ECS scale-in was killing 2-hour translation jobs. So workers drain before they stop.

  • aws
  • ecs
  • terraform
• 2026-10-05 Note
  One engine, three providers

  Rate limits caused 65% of review failures. Treating them as "retry later" stopped provider outages from becoming ours.

  • llm
  • rails
  • aws
• 2026-10-05 Note
  7.33M rows per call

  One status broadcast ran 1,013 queries and pinned Aurora at 100% CPU. The fix was not an index. EXPLAIN showed each call scanning 7.33M rows.

  • aurora
  • mysql
  • performance
• 2026-10-05 Note
  The verdict lives in code, not the prompt

  Almost trusted a plausible explanation. So pass/fail had to live in tested code.

  • agents
  • llm
  • rails