The developer will collaborate with product owners, architects, UX teams, backend/API teams, cybersecurity, QA, compliance, and operations to deliver customer-facing features such as onboarding, authentication, account servicing, payments, cards, alerts, and service requests. Create unit, integration, UI, and automated regression tests using JUnit, MockK/Mockito, Espresso, and Compose testing; support security, accessibility, performance, UAT, and production validation.