Senior Android Engineer- Hardware

Team description The Hardware tribe builds the technology that turns everyday devices into secure, reliable card readers, from Bluetooth-connected dongles to fully in-house Tap to Pay on Android. You'll join a team solving genuinely hard problems: keeping payments working across flaky Bluetooth connections, handling online and offline flows without losing a transaction. It's a chance to go deep on Android engineering in a space where reliability really matters, since every merchant depends on these readers to get paid. What you'll do Build and maintain Android applications for card readers, SDKs, and the SuperApp, covering both new features and improvements to existing systems Work on Bluetooth Low Energy connections, online and offline payment flows, and Tap to Pay functionality Refactor and modernise legacy code to improve reliability, performance, and maintainability Contribute to testing practices, including unit and integration tests, to raise overall code quality Collaborate with peers and stakeholders across the team to manage priorities and shape solutions to technical challenges You'll be great for this role if... Several years of professional Android development experience, with solid proficiency in both Java and Kotlin Strong knowledge of clean architecture principles and hands-on experience maintaining Android SDKs Experience of writing unit and integration tests, and comfort refactoring legacy code without breaking existing functionality Familiarity with CI/CD pipelines, such as GitHub Actions, and an interest in improving build and release processes Ability to adapt to ambiguity and shifting priorities, with strong communication skills for working independently with stakeholders Why you should join SumUp 🌎 Opportunity to work with SumUppers globally on large-scale fintech products used by millions of businesses worldwide, from our Berlin office. This involves an office-first setup 🌈 Commitment to Diversity and Inclusion: be p