Senior Android Payments Developer

About the role

Ubique Systems is seeking a Senior Android Payments Developer to create and maintain high‑quality point‑of‑sale (POS) applications on embedded Android and AOSP devices. The role focuses on delivering secure, performant payment solutions for a range of hardware platforms.

Key responsibilities

• Design and implement Android POS applications for embedded/AOSP terminals using clean Java/Kotlin code.
• Integrate and validate drivers and SDKs for card readers, PIN pads, NFC/contactless, EMV readers, printers and other peripherals (experience with PAX SDKs preferred).
• Develop payment flows covering authorisation, settlement, reversal and offline capabilities, handling EMV, contactless and magnetic stripe scenarios.
• Prepare certification artefacts, run test suites and coordinate with card schemes and acquirers (Visa, Mastercard, Amex, etc.).
• Migrate legacy payment codebases to modern, modular architectures while preserving backward compatibility.
• Implement 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 CI/CD pipelines for terminal images and application packages, including automated 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 devices.
• Proven experience with POS device SDKs and hardware integration, especially PAX devices.
• Deep understanding of payment standards such as EMV, NFC, PCI and card‑scheme certification processes.
• Ability to refactor legacy codebases into modular, maintainable architectures.
• Experience with performance profiling, telemetry implementation and CI/CD automation.

Required skills

• Android SDK
• Java
• Kotlin
• POS device SDKs (PAX preferred)
• EMV and NFC payment technologies
• PCI compliance and security best practices
• CI/CD pipelines and automated testing
• Device‑farm testing
• Performance profiling and optimisation