Led a staged, zero-downtime dependency-injection migration across a national airline's aging Android app, and stood up the CI and snapshot-testing foundation that made shipping it safe, so 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 change, slow to build, and slow to onboard into, right as feature demand was rising. A big-bang migration was off the table for a high-traffic app, and the team had no safety net, no enforced visual regression testing, to catch breakage from a migration of that size.