Software Engineer - Android

Gravity Payments is hiring a Software Engineer for its Payments Platform team. The role builds and maintains Kotlin-based Android payment applications and SDKs for PAX terminals, with a focus on reliable payment processing, integrations, and software quality in certified environments.

Responsibilities:

• Build and maintain Android applications and libraries in Kotlin for PAX payment terminals, including the merchant-facing payment application and the partner-facing device SDK
• Work at the integration boundary: the PAX POSLink library, BroadPOS P2PE, EMV chip application selection, encrypted card payloads, key slots, and device registration
• Design for correctness under failure. Idempotency, retry safety, bounded timeouts, crash recovery, and durable correlation between a device transaction and the partner session it belongs to
• Participate substantively in engineering design documents and code review. Raise structural concerns, distinguish them from style, and defer where the call is not yours
• Own the quality of what you ship end to end: tests, instrumentation, release notes, and the support burden it creates
• Partner with the EMV certification effort. Understand which changes require a certification conversation before they are made
• Treat AI-assisted and agentic tooling as a core competency. Use it daily, and bring what you learn back to the team

Requirements:

• 2+ years shipping production Android applications in Kotlin, including work you did not start yourself
• Structured concurrency, dependency injection, and Compose or a credible reason you are on Views
• You have shipped software where a defect has consequences: payments, banking, healthcare, identity, safety, industrial control, or comparable
• Demonstrable opinions on architecture, module boundaries, public API design, and error handling, with specific examples of a decision you made and what it cost you
• Comfort with ambiguity
• You can describe a project where the requirements were genuinely unsettled, what you did to narrow them, and what you deliberately deferred
• Evidence of long-horizon thinking: a deprecation you sequenced, a migration you finished, a dependency you refused, or a public interface you shaped knowing you could not take it back
• Active daily practice with AI-assisted and agentic tools, and a view on how engineers should use them
• Coachable
• You take direct feedback, act on it, and come back with questions
• Android development against payment terminal hardware: PAX, Clover, Sunmi, Verifone, Ingenico, Square, or comparable
• Clover application development is a direct plus
• EMV, card-present processing, tokenization, or PCI DSS scope experience
• Published or distributed an Android library or SDK that third parties consumed: Maven artifact versioning, dependency isolation, backward compatibility, and deprecation policy
• Network security work on Android: certificate pinning, mutual TLS, OkHttp interceptor chains, secure storage on device
• Experience where a release could not be rolled back quickly, and you planned around that constraint