Android Developer

We are seeking a Senior Android Payments Developer to lead development of card

acceptance applications on POS devices and play a significant role in a legacy

modernisation programme. You will design and implement robust, secure Android

software for terminals (including PAX devices), work closely with QA, product and

programme teams, and drive payment certification with major card schemes.

Key Responsibilities:

· 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

coordinate 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 rootcause analysis for critical

incidents, produce fixes and participate in postrelease 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.

Skill :

· 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 and SDKs highly desirable.

· Deep understanding of payment terminal flows, EMV transaction lifecycle,

contactless/NFC processing and implications for application logic.

· Practical familiarity with payment scheme certification processes and

requirements for Visa, Mastercard, American Express (preparing logs, test

cases, remediation).

· Awareness of industry security standards: PCI (including PCI PTS) and EMV

kernel behaviours; understanding of secure key management concepts and

HSM interactions.

· Experience with automated testing and CI/CD for mobile/embedded

applications: unit, integration, UI automation and device farm orchestration.

· Proficient with modern development toolchains: Android Studio, Gradle, Git;

experience with Jenkins/GitLab CI/Azure DevOps or equivalent.

· Competence in debugging on physical devices, serial/USB/Bluetooth/NFC

communications, and analysing logs and traces from constrained

environments.

· 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 product and

programme stakeholders.

· Experience working in regulated/financial environments (fintech, payments)

and in large enterprise delivery contexts.