Backward Batching: Fixing Slow Uploads Without Blocking Users

When Daniel was cataloguing books at his in-laws' rural house, slow uploads kept breaking his workflow rhythm. He turned to Claude Code and got a system using IndexedDB, Web Workers, and server-side job queues — but he hasn't reviewed the code yet. In this episode, we reverse-engineer what Claude probably built: a background upload runner that caches images locally, a BullMQ queue that batches Gemini API calls, and a pattern called "backward batching" that inverts the traditional dependency flow. We also tackle the uncomfortable question of how to review AI-generated code when you haven't looked at it yet. Episode #040053 — open it directly at myweirdprompts.com/040053