Senior POS Developer - Ireland Based at Expleo Group

Overview

• Expleo is seeking a Senior Android Payments Developer to lead the development of card acceptance applications on POS devices and play a key role in a legacy modernisation programme. You will design and implement secure, high-performance Android software for payment terminals (including PAX devices), collaborate with QA, product and programme teams, and drive payment certification with major card schemes.
• This is a relocation opportunity for anyone open to relocating to Ireland and is fully onsite in Nenagh, Co. Tipperary.

Responsibilities
Android POS Development

• Design and implement Android applications for POS terminals, delivering clean, maintainable Java/Kotlin code for embedded Android/AOSP-based devices.
• Integrate with POS hardware: implement and validate drivers and SDK integrations for card readers, PIN pads, NFC/contactless, EMV readers, printers and peripherals (experience with PAX SDKs expected).
• Implement payment flows: authorisation, settlement, reversal and offline-capable flows; ensure correct handling of EMV, contactless and magnetic stripe scenarios.

Certification & Compliance

• Prepare artefacts, run test suites and coordinate payment certification activities with card schemes and acquirers (Visa, Mastercard, Amex).
• Address scheme audit findings and remediation promptly.
• Implement secure coding practices and support PCI and terminal security requirements (PCI PTS, EMV kernel considerations).
• Liaise with security and HSM teams on key management interfaces.

Legacy Transformation

• Migrate and refactor legacy payment codebases to modern architectures (modularisation, services, secure SDKs), preserving backward compatibility and minimising customer impact.

Performance & Observability

• Profile and optimise application performance, improve startup times and memory usage.
• Add telemetry and diagnostics to aid support and SRE teams.

Automation & CI/CD

• Build and maintain automated build, test and release pipelines for terminal images and application packages.
• Support automated regression and device farm test runs.

Collaboration & Mentoring

• Review peers’ code, share knowledge across the team, and work closely with QA leads, programme managers and product owners to align delivery priorities.
• Participate in post-release reviews and drive root-cause analysis for critical incidents.

Qualifications

• Bachelor’s degree in Computer Science, Software Engineering, or a related field.

Essential skills

• Strong analytical skills, attention to detail and methodical approach to debugging and problem resolution.
• Effective verbal and written communication; able to prepare technical artefacts for certification and present technical trade-offs to stakeholders.
• 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.