tracer-bullets

Build features as vertical slices through all layers, verifying each slice before starting the next. From The Pragmatic Programmer: get feedback as quickly as possible. Don't build horizontal layers in isolation (all endpoints, then all UI, then all tests). Build one thin vertical path, verify it works, then expand.

Skip for single-layer changes, one-file bug fixes, or work already decomposed into ordered vertical slices by a task tracker.

| Vertical over horizontal | Build one slice through all layers, not one layer across all features | | Verify before advancing | Tests pass, page renders, round-trip works before next slice | | One slice per session | Each slice should be completable in a single agent session |

將多層特徵建構成垂直端對端切片而不是水平層。每個切片在下一個切片開始之前都會經過驗證。 使用時機：啟動任何跨越 2+ 層（DB、API、UI、測試）的任務、建立 CRUD 功能、實作多步驟流程、將功能分解為子任務或規劃實作順序。 來源：oakoss/agent-skills。