Kotlin Backend Developer

We are looking for people who want to shape the future with us. As part of SPRIND, an organization that is called the “Federal Agency for Breakthrough Innovations” but thinks like a start-up. Our goal is to create new breakthrough innovations from Germany. That means products, services and systems that make all of our lives noticeably and sustainably better. To do this, we connect new thinkers from science and business, people with outstanding ideas, special expertise and passion.

In the “EUDI Wallet Infrastructure” project, which SPRIND is carrying out on behalf of the Federal Ministry of the Interior and Community (BMI), a concept for a German overall system for the implementation of the eIDAS 2.0 regulation including a digital wallet is being developed and tested. Representatives of organized civil society, business associations and administration as well as experts from science are involved in a public consultation process that accompanies the project. As a backend developer you will be an important part in the Wallet Product team realizing this project.

Join a multidisciplinary team shaping the future of secure digital identity in Europe. You’ll play a key role in designing and building the backend architecture of a high-trust digital wallet solution used across regulated, privacy-sensitive domains.

SHAPE THE FUTURE WITH US AS BACKEND DEVELOPER (M/F/D)

FULL-TIME, REMOTE (occasional visits to Berlin/Leipzig/Frankfurt), limited until December 2026.

• Contribute to the architecture and implementation of the wallet’s backend services, including: Remote trust anchor (Cloud HSM) integration, Wallet and Credential lifecycle, Vulnerability management, System telemetry and statistics
• Design and implement secure, scalable, and reliable backend components, focusing on quality and resilience.
• Develop and maintain test suites across system levels, including functional, load, and performance testing.
• Evaluate and evolve existing components, replacing or refining them where needed to meet new security and scalability requirements.
• Collaborate closely with mobile/backend developers, security engineers, and architects in an agile, international team, working across German and EU government bodies and supporting organizations.
• Contribute to concise and clear technical documentation for internal processes, certification efforts, and public specifications.

• Proven ability to deliver value in high-stakes, regulated environments, with a strong focus on backend systems that prioritize security, scalability, and compliance
• 10+ years of backend development experience, including 3+ years of Kotlin, designing and building robust, scalable, and secure REST APIs
• Deep knowledge of modern cryptography, secure protocol implementation, and identity management standards (e.g., OAuth2, OpenID Connect, Verifiable Credentials)
• Strong security mindset with hands-on experience building and reviewing security-sensitive applications, conducting threat modeling, and mitigating common web/API vulnerabilities
• Skilled in relational database design and SQL query optimization, ensuring performance and reliability under high load and complex transactional scenarios
• Experienced with scalability planning, load testing, and backend analytics, enabling insight-driven performance tuning and operational resilience
• Active contributor to the open source communities, including leadership in public technical discussions, issue triage, and contribution to standardization efforts
• Comfortable working in DevOps environments, collaborating closely with ops teams to improve infrastructure, deployment pipelines, and observability across environments
• Excellent communicator, able to bridge the gap between technical depth and practical decision-making, whether through design docs, code, or team discussions

Bonus Skills:

• Experience with Digital Credentials / OpenID / OAuth / Verifiable Credentials
• Knowledge of Hardware Security Modules (HSMs) and cryptographic key management
• Familiarity with device attestation mechanisms like Play Integrity and iOS DeviceCheck
• Hands-on experience with DevOps, CI/CD pipelines, and cloud-native operations

• The attractive remuneration is based on the responsibility of the position
• Flexible working hours and remote work options
• Access to conferences, team events, and a supportive work culture.

Would you like to help develop our EUDI Wallet Infrastructure project? We look forward to receiving your application.

With the interim Group you get the correct talents, who really fit to the positions and that without a success commission.