Led a staged, zero-downtime dependency-injection migration across a national airline's aging Android app, and built the CI and snapshot-testing foundation that made shipping it safe. Feature delivery sped up on a codebase that had been slowing every team down.
Context and stakes
The airline's Android app was years old and carried a large, tightly-coupled dependency-injection setup from an earlier era. The app served millions of travelers, so the codebase could not go offline for a rewrite. Modernization had to happen underneath live delivery.
Problem
The legacy setup made the codebase slow to build and slow to change, right as feature demand was rising. A big-bang migration was off the table for an app carrying that much traffic, and there was no safety net: no enforced visual regression testing to catch what a migration of that size would break.