Freelance Senior Java Backend Engineer opdracht

Senior Java Engineer

Help build reliable, real-time data products that contribute to safer, more accessible and more sustainable travel in the Netherlands. As a Senior Java Engineer, you’ll develop robust, scalable backend services that process millions of traffic messages a day.

What you’ll do

• Develop and maintain backend services and microservices using Java and Spring Boot.
• Build event-driven solutions to process real-time traffic data with Kafka.
• Develop functionality to process, enrich and distribute data.
• Contribute to an Angular frontend application that visualises data streams.
• Build scalable, maintainable and testable software solutions.
• Work with your team on CI/CD, monitoring and platform improvements.
• Maintain and improve software quality and technical standards.
• Contribute to architecture, technical innovation and process optimisation.
• Develop your knowledge of streaming data, data modelling and distributed systems.

Technology

• Java 21+ and Spring Boot 3 and 4
• Event-driven architecture with Strimzi Kafka, Kafka Streams, Kafka Connect and RabbitMQ
• Avro and PostgreSQL
• Grafana, Prometheus, Loki, Tempo and OpenTelemetry
• Kubernetes on Azure AKS
• Angular

What you bring

• A completed relevant university degree, such as Computer Science or Software Engineering.
• At least five years of production experience with Java and Spring Boot within the past ten years.
• At least two years of hands-on experience with event-driven architectures using Apache Kafka and Kafka Streams within the past five years.
• Experience working in Kubernetes environments; experience with AKS is an advantage.
• A strong focus on clean code, testability and scalability.
• The technical depth and perspective to understand complex systems and act as a sparring partner for your team.
• Experience with or an interest in Angular.
• Experience with Azure DevOps pipelines and ArgoCD.
• Experience working in an Agile environment; SAFe experience is an advantage.

How you work

• You combine technical expertise with a pragmatic approach, knowing when to pursue perfection and when a simpler solution is better.
• You think in systems and end-to-end data flows, not just individual components.
• You enjoy sharing your knowledge and helping your colleagues grow.
• You bring a positive attitude and a good sense of humour.
• You value quality and simplicity, and avoid unnecessary complexity.
• You thrive in an environment that combines freedom with responsibility.

What makes this role distinctive

• Your work supports data products that contribute to traffic safety and sustainability in the Netherlands.
• You’ll play a key role in a multidisciplinary team, with the opportunity to make a direct impact through your technical decisions.
• You’ll work with a modern event-driven technology stack and real-time data at national scale.
• You’ll have room to experiment with Claude, new tools, frameworks and methods, and help improve how the team works.