Integration Developer (Kafka & Java)

Integration Developer - Kafka, Java, JSON, Jolt, Kubernetes, TLS certificates and mTLS

Location: Stockholm, Sweden, hybrid 2 to 3 days onsite per week

Contract: Freelance contract, 12 months, extendable

We are looking for an Integration Developer with hands on experience building and operating event driven integrations using Apache Kafka and Java. The role involves stream processing with Kafka Streams, JSON transformations using Jolt, secure connectivity using TLS and OIDC, and deployment and operations on Kubernetes.

Responsibilities

• Develop and maintain integration services using Apache Kafka and Java
• Build stream processing pipelines using Kafka Streams, including stateful processing, joins, and windowing where required
• Design and implement Jolt transformations for JSON payload mapping
• Implement secure communication using TLS and mTLS certificates, including keystore and truststore management and certificate rotation support
• Integrate authentication and authorization using OIDC, including token handling and validation where required
• Deploy and operate services on Kubernetes, including configuration, secrets, scaling, monitoring, and troubleshooting
• Collaborate with SAP and downstream consumers to align on payload design, performance, and error handling patterns

Required Skills

• Strong experience with Apache Kafka, including producers, consumers, topics, partitions, offsets, retries, and error handling
• Hands on experience with Kafka Streams and the Kafka Streams library in Java
• Experience with Jolt for JSON transformations, including creating, testing, and maintaining Jolt specifications
• Security experience with TLS certificates and mTLS, including keystore and truststore handling and certificate lifecycle basics
• Understanding of OIDC fundamentals, including access tokens, validation, and service integration
• Kubernetes fundamentals including deployments, services, ingress, config maps, secrets, and scaling

Nice to Have

• Experience with Schema Registry and schemas such as Avro, Protobuf, or JSON Schema
• Experience with Kafka Connect and connector based integrations
• Experience with CI/CD pipelines such as Jenkins or GitHub Actions and Helm
• Experience with observability tools including logging, metrics, and tracing using Prometheus, Grafana, or ELK