Java/Android Developer Lisboa

Java/Android Developer
Lisboa
Lisboa, Lisboa, Portugal

1. The Role:

We're hiring a
Java/Android Developer
to help build the next generation of SDKs for Android-based payment terminals. This role sits at the intersection of software engineering and secure payments, where you'll develop technology that powers contactless, chip, and magstripe transactions across global payment networks.

You'll implement transaction flows and secure key injection processes (RKI), ensuring our solutions align with the highest standards of EMV and PCI. You'll also contribute to payment gateway integration, giving you visibility into both
- level and backend payment flows.

If you're passionate about Android development, thrive in a
- security fintech environment, and want to make a real impact on how payments happen worldwide, we'd love to meet you.

2. Key Responsibilities:

• SDK Development
  : Design and implement a modular SDK for Android-based payment terminals.
• Transaction Flows
  : Build and optimize features for CTLS, chip, and magstripe transactions, compliant with EMV specifications.
• Security & Cryptography
  : Implement secure cryptographic operations and key injection workflows (RKI).
• Integration Support
  : Provide clean APIs and documentation for
  - party developers integrating with the SDK.
• Certification Readiness
  : Support QA and compliance teams in preparing for EMV Level 3 and scheme certifications (Visa, Mastercard, AMEX, etc. ).
• Testing & QA
  : Develop automated tests and use simulators/emulators to validate SDK functionality across transaction scenarios.
• Continuous Improvement
  : Monitor, debug, and optimize SDK performance for reliability, security, and maintainability.
• Optional Plus
  : Contribute to payment gateway integration (ISO 8583, host protocols, transaction routing) when needed.

3. Technical Skills Required:

• Strong Java (Android) development background.
• Experience developing SDKs for Android payment terminals.
• Solid understanding of EMV transaction flows (CTLS, chip, magstripe).
• Familiarity with TLV structures, APDU messaging, and EMV specs.
• Experience implementing cryptographic operations and RKI workflows.
• Understanding of EMV Level 3 certification and scheme approval processes.
• Awareness of PCI DSS and PCI PTS requirements in terminal software.
• Skilled in unit and integration testing for payment applications.
• Preferred/Plus
  : Experience with payment gateway integration (ISO 8583, JSON/REST APIs, routing).

4. Why Join Us?

• Work on
  - edge
  fintech technology
  at the heart of global payments.
• Be part of a
  highly skilled,
  - driven engineering team
  .
• Gain exposure to both
  
  - side SDKs
  and
  payment gateway systems
  .
• Contribute to solutions that are used
  by millions of people every day
  .

summary of the role, what success in the position looks like, and how this role fits into the organisation overall.