Git Worktrees + Headless AI Sessions: A Pattern for Parallel Code Generation

The serial bottleneck You have a plan with six batches of AI-driven work: build the auth module, write its tests, scaffold the dashboard, add the API routes, wire up the middleware, write the integration tests. Batches 1-3 have nothing to do with batches 4-6. No shared files, no dependency chain, no ordering constraint. But they run one at a time. Twenty minutes of wall-clock time for work that could finish in ten. This is the embarrassingly parallel problem. A single Claude Code session is inherently serial - it processes one task, commits, moves to the next.