Senior POS Developer

Responsibilities

• Develop and maintain Android POS applications (Java/Kotlin) for embedded/AOSP devices, integrating with payment hardware (card readers, NFC, EMV, printers) using SDKs (e.g. PAX).
• Implement end-to-end payment flows (authorisation, settlement, reversal, offline) with full EMV/contactless support.
• Lead certification and compliance activities (Visa, Mastercard, Amex), ensuring PCI/PTS and secure coding standards, and working with security/HSM teams on key management.
• Modernise legacy payment systems into modular, secure architectures with minimal customer impact.
• Optimise performance, add telemetry, and support observability.
• Build and maintain CI/CD pipelines, automated testing, and release processes.
• Collaborate across teams, review code, and support incident analysis and continuous improvement.

Qualifications & Skills

• Degree in Computer Science or related field.
• Strong analytical, debugging, and communication skills.

Experience

• 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—experience with PAX devices highly desirable.
• Deep understanding of payment terminal flows, EMV transaction lifecycle, contactless/NFC processing.
• Familiarity with payment scheme certification processes (Visa, Mastercard, Amex).
• Awareness of PCI DSS, PCI PTS and EMV kernel behaviours; understanding of secure key management and HSM interactions.
• Experience with automated testing and CI/CD for mobile/embedded applications.
• Proficient with modern toolchains: Android Studio, Gradle, Git; experience with Jenkins/GitLab CI/Azure DevOps.
• Competence in debugging on physical devices, handling serial/USB/Bluetooth/NFC communications, and analysing logs from constrained environments.
• Experience in the payments domain (e.g. Nexo Standards, EMVCo, PCI/PTS compliance) is highly desirable.