(Senior) Kotlin Backend Engineer - User Management

• Design and implement Kotlin services for authentication, authorisation, and access management across the MOIA platform.
• Contribute to the stability, accuracy, and observability of identity and access services.
• Collaborate on React-based front-ends with shared ownership across teams.
• Take end-to-end responsibility for features-from design and implementation to deployment and operations.
• Lead design discussions, mentor peers, and elevate code quality and technical decision-making.
• Promote best practices in code reviews, test automation, observability (metrics, logs, traces), and monitoring.
• Work in agile, iterative cycles with strong team ownership and autonomy.

• Strong Kotlin backend experience, or solid JVM background with readiness to transition to Kotlin.
• Experience building services on AWS with serverless components (e.g. Lambda, DynamoDB, SQS) or similar cloud providers.
• Familiarity with modern authentication technologies (OAuth2, OIDC ).
• Understanding of distributed systems and a passion for clean, scalable, simple architectures.
• Experience with React or other modern frontend frameworks (Vue, Angular).
• Appreciation of DevOps practices: infrastructure as code, CI/CD pipelines, automated observability.
• Strong collaboration skills, openness to feedback, and fluent English communication.

Nice-to-haves

• Exposure to gRPC, GraphQL, and REST APIs.
• Comfort with, or eagerness to learn, Kubernetes.
• Knowledge of privacy-by-design principles, GDPR awareness, and secure coding practices.
• Experience with RBAC / ABAC , policy engines (e.g. OPA ), or secrets management.
• Previous on-call, incident response, or SLO/ SLI definition experience.
• Mentoring experience or ability to lead design discussions.

We welcome applicants from diverse backgrounds- even if you don't meet every requirement. If you're excited about the role and MOIA's mission, we'd love to hear from you!

• Competitive salary (including bonus)
• Hybrid work setup: Work from home or one of our offices - you and your team decide how often to meet, blending flexibility with collaboration!
• Flexible working hours and the possibility of flexible work arrangements depending on your needs (parenting, care work, volunteering, etc.)
• Budget and monthly expense allowance for home office setup
• Possibility of remote work from outside Germany for up to 6 weeks per year from over 35 countries - learn more in our blog!
• Public transport ticket (fully subsidized "Deutschlandticket") for commuting and travelling throughout Germany and discount on MOIA rides
• Subsidized fitness club membership or bike leasing
• Learning environment with continuous learning days, job rotation, trainings and workshops, coaching, conferences, books, and language classes
• Mental health support, 1:1 sessions with external professionals and mental unload workshops
• 30 vacation days, sabbatical and unpaid leave option
• Relocation support with service provider (visa, administration, etc.)
• Dog-friendly offices

For student & internship positions, we have an adjusted set of benefits. You can find them here.

Join us as a (Senior) Kotlin Backend Engineer (m/f/d) in our User Management team and help shape the future of autonomous mobility! The User Management team is the gateway to our app platform , playing a crucial role in building trust and ensuring a secure, seamless user experience. We are responsible for engineering the authentication and access control systems that protect our users and their data. You'll join a dedicated, cross-functional team of experts in authentication, data privacy, distributed systems, and modern backend development. Together, we design, build, and run the scalable, resilient services that form the foundation for every customer interaction on our platform., We are a member of Charta der Vielfalt and are dedicated to actively fostering a workplace that celebrates and promotes diversity in various aspects such as age, gender identity, race, sexual orientation, physical or cognitive ability, and ethnicity. At MOIA, we embrace a culture where people are accepted, respected, valued, appreciated, and included. In our commitment to promoting diversity and inclusivity, we regularly provide unconscious bias training to all our employees. Furthermore, we continuously strive to enhance our hiring process by ensuring a diverse hiring panel. Our Future Work model Since we love to collaborate, it is clear to us that we don't want to become a fully remote company, but we also don't need to spend every day of the week in the office to do a great job. Our current hybrid work approach focuses on adapting to different needs, including increased flexibility that works best for the teams and the individuals with as much self-determination as possible. Get more insights on how we work on our blog to find out more about our hiring process or follow us on Instagram for a look inside MOIA., At MOIA we're reimagining the future of mobility - safe, autonomous and tailored to the needs of cities and their people. As a tech company with more than 400 employees, we build mobility solutions that truly move cities forward. We launched our ridepooling service in Hamburg in 2019 and have been part of the city's public transport system since 2023. Since launch, we have transported over 12 million passengers. Currently, MOIA is evolving from a mobility provider to a tech provider offering a scalable and safe turnkey solution for autonomous driving. With office locations in Berlin and Hamburg, our diverse and international team comprising more than 60 nationalities works together toward that shared mission. MOIA is more than a technology provider - we are a partner to cities and public transport operators committed to creating more livable spaces and delivering mobility solutions that are reliable, safe and comfortable.