Senior Consultant

Design and implement Android applications for point-of-sale terminals deliver clean, maintainable Java/Kotlin code that runs on embedded Android and AOSP-based POS 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 and device-specific APIs expected). Payment flow implementation author authorisation, settlement, reversal and offline-capable flows; ensure correct handling of EMV, contactless and magnetic stripe scenarios. Support payment certification prepare artefacts, run test suites and co-ordinate certification activities with card schemes and acquirers (Visa, Mastercard, American Express and others); address scheme audit findings and remediation. Contribute to legacy transformation migrate and refactor legacy payment codebases to modern architectures (modularisation, services, secure SDKs), preserving backward compatibility and minimising customer impact. Security and compliance implement secure coding practices, support PCI and terminal security requirements (PCI PTS, EMV kernel considerations), and liaise with security and HSM teams on key management interfaces. Performance, reliability and observability profile and optimise application performance, improve startup times and memory usage, and add telemetry/diagnostics to aid support and SRE teams. Automation and 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. Defect resolution and production support drive root-cause analysis for critical incidents, produce fixes and participate in post-release reviews. Mentoring and collaboration review peers’ code, share knowledge across the team, and work closely with QA leads, programme managers and product owners to align delivery priorities.