Incremental Shipping

Overview

A workflow for landing large changes as small, reversible increments. The skill exists because the most common shipping failure isn't a missing test or a bad deploy — it's a 1500-line PR that bundles a feature, a refactor, and a config change, takes three days to review, and lands with a regression nobody isolated. Incremental shipping splits that into thin vertical slices behind feature flags, plus a refactor-with-evidence section for behavior-preserving changes that need their own discipline (test deltas, perf measurements). Used after write-plan and test-first, before code-review-loop.

When to Use

• A feature plan has 5+ tasks and would otherwise ship as one PR
• A migration must run alongside existing code for a transition period
• A refactor changes structure but should preserve behavior; you need to prove it
• A change is risky enough that you want a kill switch in production