Use Case #30: Multi-Repo Sync

We have a shared component library. 6 apps use it. When the library updates, 6 repos need updates.

This used to be a half-day task.

The Sync Process

Step 1: Update Detection - Claude checks the shared library for new version, changelog, and breaking changes.

Step 2: Impact Analysis - For each consuming repo: what components are used? Which are affected by changes?

Step 3: Update Propagation - Clone each repo. Update dependency. Run build. Identify breaks.

Step 4: Fix Breaking Changes - Each repo might break differently. Claude adapts to each codebase's patterns.

Step 5: Verification - Build passes. Tests pass. Visual spot-check on dev server.

Step 6: Commit and PR - Create PRs with changelog and migration notes.

Example Update

Library update: Button component API changed. Now requires 'variant' prop.

Repo 1 - 47 Button usages. All used default styling. Added variant="default" to all.

Repo 2 - 23 Button usages. Already had variant prop (coincidence). No changes needed.

Repo 3 - 156 Button usages. Mixed patterns. Claude analyzed each usage context to determine correct variant.

Time Comparison

The Real Value

Not just time saved. Consistency. Every repo gets the same update, applied the same way, with the same verification.

---

Multi-repo sync pattern developed December 2025.