Mobile Developer Engineer

We are looking for a Mobile Developer Engineer who will take ownership of the end-to-end development of secure, high-quality mobile SDKs and applications for Android (Kotlin) and/or iOS (Swift), with the opportunity to contribute across both platforms., * Design, develop, and maintain native mobile SDKs/libraries (Kotlin, Swift).

• Design, develop, and maintain native mobile applications to showcase these SDKs.
• Participate in code reviews, pair programming, and contribute to TDD and E2E testing.
• Work with hardware features such as secure elements and NFC.
• Integrate with RESTful APIs and collaborate with backend teams.
• Set up and master CI/CD tools, participate in secure code reviews, and contribute to
• documentation.
• Follow Scrum project workflows and engage in daily standups.
• Deliver features from ideation to deployment, maintaining security and compliance.
• Troubleshoot and optimize the CI/CD pipeline for quality and speed.

• Proficient in native Android (Kotlin) and/or iOS (Swift) development.
• Willingness to assist across both platforms if needed.
• Experience with mobile development tooling (IDEs, test frameworks, emulators).

Nice-to-Haves:

• Cross-platform experience (Flutter preferred).
• Familiarity with hardware features (NFC, BLE), developing mobile libraries, or native code integration.
• Understanding of Docker, Figma-based UI implementation, Rust, smart cards, secure elements, or byte-level debugging of binary protocols., You write secure, test-driven code, enjoy collaborating with teammates, mentor others, and are comfortable exploring new tools and technologies in a fast-paced mobile environment.

Days 0-30: Orientation & Foundations

• Get familiar with company culture and security basics.
• Attend intro sessions in password policies, secure code review, incident response.
• Configure your development environment (IDEs, emulators, libraries, CI tools).
• Run local builds for iOS, Android, and backend.
• Review key security policies and study product user flows, architecture diagrams, API specs.
• Shadow senior developers and join product demos.

Days 31-60: Deepening Skills & First Contributions

• Participate in workshops on secure coding and best practices (OWASP Mobile top risks).
• Write code using TDD for small features and bugfixes.
• Engage in pair programming with a mentor focused on security and test cases.
• Get hands-on with E2E tests, CI/CD mastery, and contribute.
• Take ownership of a real ticket and participate in a security code review.
• Document your features or tests.

Days 61-90: Autonomous & Secure Contribution

• Own delivery of a feature end-to-end (from coding, TDD, peer review, E2E, to deployment).
• Fix a medium-level security issue in the codebase and propose new tests.
• Lead a security retrospective or sharing session.
• Optimize part of the CI/CD workflow (caching, deployment automation, test speed).
• Mentor newcomers on secure coding basics.
• Help refine Scrum processes and share lessons learned through onboarding documentation.

What's great about working with us:

• Culture and diversity: Join a people-oriented environment with different nationalities and a great team spirit, flat hierarchies (everyone speaks to everyone). Equal Opportunity Employer and LGBT+ friendly.
• Team: An opportunity to shape our engineering culture and work with a passionate, mission-driven team. Collaboration with a diverse and very international team of outstanding people.
• Global Collaboration: Work collaboratively with stakeholders around the globe.
• Impactful Work: You will have the opportunity to participate in and shape a global lighthouse project in the domain of digital currencies.
• Career Development: Benefit from continuous training, coaching, and talent development programs.
• Social Benefits: Flexible compensation (transport tickets, training, private insurance), etc.
• Own canteen: Take a break with our breakfast and lunch service: choose between a wide range of menus, salad desk, and sandwiches service. Nicely priced!
• Work-Life Balance: Flexible working hours with the option for remote work (Mon-Thu 8:30 - 17:30 and Fri 8:30 - 15:30; 3 days of remote work).
• Location: El Prat de Llobregat. Easy communication by private transport or public transport: Bus 88, 110, PR4 and Metro L10S (ZAL/Riu Vell).