Chapter 6: Observability and the SQLite lock hunt
- Chapter 6a: instrument first, find the stall
Chapter 6, part 1: workflow telemetry, and the enrichment stall where 45 stories sat pending with a dead worker — PRs #35–39.
- Chapter 6b: hunting 'database is locked'
Chapter 6, part 2: the SQLite lock hunt — wrong first hypothesis, instrumentation, transaction splits, retry_locked — PRs #40, #43.
- Chapter 6c: making the pipeline visible
Chapter 6, part 3: a live pipeline visualizer, a per-story step log merging every event source, and enrichment provenance — PRs #41, #42, #44.