Senior Backend Engineer

What you'll do

• Design, develop, and maintain secure, scalable backend services and APIs using Kotlin and Spring Boot
• Build and operate event-driven integrations via Apache Kafka including producers, consumers, Kafka Streams, and Avro schemas with exactly-once semantics
• Own data models, query optimisation, and schema migrations across PostgreSQL and MySQL
• Integrate services with observability, CI/CD, and DevOps tooling; support deployment and monitoring on OpenShift/Kubernetes
• Apply security best practices in OAuth2/OIDC, authentication, authorisation, and encryption
• Conduct code reviews, uphold engineering standards, and mentor junior engineers
• Produce high-quality technical documentation covering design, implementation, and API contracts
• Influence platform-wide architectural decisions
• Act as a technical reference for the squad and wider backend chapter

Requirements

• 5+ years of professional backend engineering experience
• Proficiency in Kotlin
• Strong hands-on experience with Spring Boot (Spring MVC, Security, Data JPA, Cloud, Actuator)
• Solid Apache Kafka experience including Kafka Streams, Schema Registry, and exactly-once semantics
• Proficiency with PostgreSQL and MySQL: data modelling, query plans, replication, and working with connection pools (HikariCP)
• Practical experience with Kubernetes or OpenShift
• Sound understanding of distributed systems, microservices architecture, and design patterns
• Familiarity with OAuth2/OIDC and backend security fundamentals
• Proficiency with Git and CI/CD practices
• German B2+ for team communication, documentation, and stakeholder interaction
• English business proficient

Tech stack

Benefits