Senior Android Payments Developer

About the role

We are looking for a Senior Android Payments Developer to design and deliver high‑quality Android applications for point‑of‑sale (POS) terminals. The role focuses on building secure, performant payment solutions that run on embedded and AOSP‑based devices and meet certification requirements of major card schemes.

Key responsibilities

• Design and implement Android applications for POS terminals, delivering clean, maintainable Java/Kotlin code.
• Integrate with POS hardware, including card readers, PIN pads, NFC/contactless, EMV readers, printers and other peripherals (experience with PAX SDKs preferred).
• Implement payment flows such as authorisation, settlement, reversal and offline‑capable scenarios, handling EMV, contactless and magnetic stripe transactions.
• Prepare certification artefacts, run test suites and coordinate with Visa, Mastercard, American Express and other acquirers.
• Migrate and refactor legacy payment codebases to modern, modular architectures while preserving backward compatibility.
• Apply secure coding practices and support PCI and terminal security requirements, collaborating with security and HSM teams.
• Profile and optimise application performance, improve startup times, memory usage and add telemetry for support and SRE teams.
• Build and maintain automated CI/CD pipelines for terminal images and application packages, including regression and device‑farm testing.
• Lead root‑cause analysis for critical incidents, produce fixes and participate in post‑release reviews.
• Mentor peers, review code and collaborate with QA leads, programme managers and product owners.

Required profile

• Strong hands‑on Android development experience (Java and Kotlin) on embedded/AOSP variants used in POS devices.
• Proven experience with POS device SDKs and hardware integration, preferably with PAX devices.
• Deep understanding of payment terminal flows, EMV transaction lifecycle and contactless/NFC processing.
• Experience driving payment certification cycles with major card schemes and acquirers.
• Ability to migrate legacy code to modern architectures while minimising service disruption.
• Familiarity with PCI PTS, EMV kernel considerations and secure key‑management interfaces.
• Strong debugging, performance profiling and observability skills.
• Experience with automated build, test and release pipelines (CI/CD).
• Excellent collaboration and mentoring abilities.

Required skills

• Java
• Kotlin
• Android SDK / AOSP
• POS device SDKs (e.g., PAX)
• EMV kernel integration
• NFC / contactless processing
• PCI PTS compliance
• Hardware Security Module (HSM) integration
• CI/CD tools (e.g., Jenkins, Gradle)
• Git version control