Android Engineer

Wallee Group is a leader in advanced payment solutions, providing robust, scalable, and secure payment technology across multiple markets. Our solutions power payment experiences across Android-based payment terminals, mobile devices, and integrated merchant environments.

With teams across several countries, we work collaboratively to build reliable payment technology that operates in highly regulated and security-critical environments.

Wallee is looking for an experienced Android Engineer to join our payment terminal engineering team in Vilnius.

You will work primarily on our Android-based payment terminal platform, developing and maintaining software that sits at the heart of payment processing on physical terminals.

This is not a typical consumer Android application role. You will work close to the Android platform, payment applications, terminal hardware, network communication, payment protocols, and security-sensitive transaction flows.

You will collaborate with engineers across Android, TypeScript, backend, payment protocols, QA, and certification to deliver reliable software used on payment terminals in production.

• Build Payment Terminal Software: Develop and maintain Android applications and components running on dedicated payment terminals.
• Work Across the Platform: Integrate Android components with payment applications, device services, hardware interfaces, APIs, and communication protocols.
• Develop Reliable Transaction Flows: Implement and troubleshoot payment functionality where correctness, stability, and predictable behaviour are critical.
• Champion Security: Work with security-sensitive systems involving TLS, certificates, cryptographic operations, secure key handling, and PCI requirements.
• Solve Complex Problems: Investigate issues across application, Android platform, device, network, and payment protocol layers.
• Drive Engineering Quality: Review code, improve architecture, write automated tests, and help maintain a reliable and maintainable codebase.
• Collaborate Across Teams: Work closely with Product, QA, certification teams, and other engineers to turn payment requirements into production-ready solutions.
• Provide Technical Expertise: Support complex technical investigations and help other teams understand terminal behaviour, APIs, and integration requirements.

• Strong Android Experience: Solid professional experience developing Android software using Kotlin and Java.
• Android Platform Knowledge: Good understanding of Android application architecture, services, lifecycle, IPC, threading, networking, and debugging.
• Engineering Fundamentals: Ability to design maintainable software, understand existing complex systems, and confidently troubleshoot production issues.
• Network Knowledge: Practical experience with TCP/IP, HTTP, and TLS.
• Security Mindset: Understanding of security fundamentals such as encryption, certificates, symmetric/asymmetric cryptography, hashing, and secure data handling.
• Quality First: You write readable, maintainable, documented, and well-tested code rather than simply making things work.
• TypeScript: Experience with TypeScript is a strong advantage, as parts of our payment terminal stack use it.
• Communication: Professional fluency in English and the ability to collaborate effectively in an international engineering environment.

Experience with payment terminals, payment systems, embedded Android devices, POS systems, EMV, PCI, or payment protocols is an advantage, but not required.