Senior Android Payments Developer

Role: Senior Android Payments Developer

Location: Dublin, Ireland

Type: Contract

Job Responsibilities:

• Android POS Application Development: Design, develop, and maintain robust Android applications using Java and Kotlin for embedded Android and AOSP-based POS devices.
• POS Hardware Integration: Integrate and validate POS hardware and device SDKs, including card readers, PIN pads, NFC/contactless interfaces, EMV readers, printers, and other peripherals. Experience with PAX or comparable POS platforms is highly desirable.
• Payment Flow Implementation: Develop and support payment flows covering authorisation, settlement, reversal, and offline-capable transactions, including EMV, contactless, NFC, and magnetic-stripe scenarios.
• Payment Certification: Prepare certification artefacts, execute test scenarios, analyse results, and coordinate certification activities with payment schemes, processors, and acquirers. Investigate certification issues and implement required remediation.
• Legacy Modernisation: Refactor and migrate legacy payment components to modern, maintainable architectures, including modularisation, service-based components, and secure SDK integrations, while maintaining backward compatibility and minimising operational disruption.
• Security and Compliance: Apply secure development practices and support relevant PCI and payment-terminal security requirements. Work with security and HSM teams on secure key-management interfaces and related integrations.
• Performance and Reliability: Profile and optimise applications for startup time, memory consumption, responsiveness, and overall reliability. Implement telemetry, diagnostics, and logging to support production operations and SRE teams.
• Automation and CI/CD: Develop and maintain automated build, test, and release pipelines for terminal applications and device software. Support automated regression testing and device-farm execution.
• Production Support: Lead root-cause analysis for critical production issues, develop and validate fixes, and contribute to post-release reviews and continuous improvement.
• Technical Leadership and Mentoring: Conduct code reviews, mentor engineers, establish engineering best practices, and collaborate with QA, product, programme, and engineering stakeholders to align technical delivery with business priorities.

Knowledge, Skills and Experience

• Strong hands-on experience developing Android applications using Java and Kotlin , particularly for embedded or AOSP-based environments.
• Proven experience integrating POS device SDKs and hardware , including card readers, PIN pads, NFC/contactless interfaces, EMV readers, printers, and related peripherals.
• Experience with PAX devices and SDKs or comparable Android-based POS platforms is highly desirable.
• Strong understanding of payment-terminal transaction flows and the EMV transaction lifecycle, including contactless/NFC processing and its impact on application logic.
• Practical experience with payment certification and acquirer testing , including preparation of test evidence, transaction logs, test cases, defect analysis, and remediation.
• Familiarity with relevant payment and terminal security standards , including PCI requirements, PCI PTS concepts, EMV kernel behaviour, secure key management, and HSM integrations.
• Experience implementing automated testing and CI/CD for mobile or embedded applications, including unit, integration, UI, regression, and device-farm testing.
• Proficiency with modern development tools including Android Studio, Gradle, and Git .
• Experience with CI/CD platforms such as Jenkins, GitLab CI, Azure DevOps , or equivalent tooling.
• Strong debugging skills on physical devices, including experience with USB, serial, Bluetooth, NFC , device logs, traces, and constrained embedded environments.
• Strong analytical and problem-solving skills, with a methodical approach to debugging complex payment and hardware-integration issues.
• Excellent written and verbal communication skills, including the ability to produce technical certification artefacts and explain technical trade-offs to product and programme stakeholders.
• Experience working within payments, fintech, banking, or other regulated environments , preferably within large-scale enterprise technology programmes.

Educational & Professional Requirements

• Bachelor’s degree in Computer Science, Software Engineering, Engineering , or equivalent practical experience.
• Relevant certifications in Android, payments, EMV, PCI, or related disciplines are advantageous.
• Demonstrable experience delivering payment-terminal software and participating in payment-scheme certification, processor testing, or acquirer acceptance testing is highly desirable.