Senior Kafka Engineer

About Justera Group
Justera Group AB is a leading Swedish IT consulting firm with great experience specializing in building high-performing technology teams and delivering end-to-end IT solutions. Led by dynamic female executives, Justera Group focuses on helping businesses harness the power of digital technologies to continuously evolve in today’s rapidly changing economy. The company has deep expertise in IT consultancy, software development, and recruitment services, providing clients with purpose-driven, well-trained consultants who consistently deliver efficient and effective results. Justera Group manages the entire talent lifecycle, from hiring to ongoing management, ensuring the right fit for each project on time and within budget. With their strong commitment to quality, collaboration, and client success, Justera Group is a trusted partner for technology innovation across Sweden.

About the Role:
We are looking for a Senior Kafka Engineer to join an integration and platform engineering team responsible for building, operating, and continuously improving critical integration and messaging capabilities used by multiple development teams.

The role focuses on Apache Kafka, HiveMQ, Kubernetes, platform stability, automation, self-service, security, and end-to-end operational ownership. You will be responsible for designing and maintaining highly available messaging platforms, automating operational processes, improving observability, and ensuring reliable and scalable platform performance.

The position is primarily platform-focused rather than application-development focused, although you will collaborate closely with development teams and may contribute to customer projects when required.

Key Responsibilities:

• Design, deploy, operate, and maintain multi-cluster and multi-region Apache Kafka environments running on Kubernetes, using Strimzi Operator or similar technologies.

• Administer and maintain enterprise HiveMQ MQTT broker environments.

• Drive the upgrade lifecycle for Kafka, Strimzi, and HiveMQ, including minor and major version upgrades and security patching.

• Coordinate platform patching activities to mitigate vulnerabilities while maintaining application availability.

• Develop and maintain custom Kafka Connect Source and Sink connectors for data integration between legacy systems and cloud environments.

• Define and implement Kafka scaling strategies, node affinity, topology spread constraints, and persistent volume configurations for I/O-intensive workloads.

• Manage Kafka broker partition layouts, topic configurations, compaction, retention, segmentation, and cluster-wide resource allocation.

• Design and implement high-availability and disaster-recovery solutions, including cross-region replication and automated failover.

• Manage and enforce data governance using Schema Registry, including Avro, Protobuf, and JSON Schema.

• Design messaging traffic routing through ingress and edge technologies such as Envoy Gateway or custom proxies.

• Implement Kafka security controls including ACLs, SASL authentication, RBAC, OAuth/OIDC, and API management integrations.

• Implement and maintain security mechanisms such as mTLS, SSL/TLS, SASL/SCRAM, and certificate-based authentication.

• Build and maintain observability solutions using Prometheus, Grafana, Splunk, Fluent Bit, and/or OpenTelemetry.

• Create dashboards and monitoring solutions for key Kafka and infrastructure KPIs.

• Develop proactive alerting for issues such as Kubernetes node failures, JVM memory degradation, disk capacity thresholds, storage problems, consumer lag, and other cluster anomalies.

• Perform Root Cause Analysis (RCA) following platform incidents and implement preventive measures and automated guardrails.

• Provide Tier 3 support for complex Kafka and integration issues, including consumer lag, rebalance loops, performance issues, and network bottlenecks.

• Act as a technical subject matter expert for development teams working with Java and Spring Boot, advising on Kafka Producer/Consumer configurations, idempotency, acknowledgements, batching, schemas, and performance.

• Ensure platform stability, scalability, performance, reliability, and cost efficiency.

• Build and maintain reusable GitHub Actions CI/CD pipelines for validating, testing, linting, and deploying infrastructure and Kafka-related configurations.

• Implement event-driven application scaling using technologies such as KEDA, based on Kafka lag and throughput metrics.

• Apply Infrastructure as Code principles using Helm, Terraform, and related tooling.

• Package and manage reusable Helm resources and OCI artifacts.

• Build developer self-service capabilities allowing teams to safely provision topics, schemas, credentials, and other messaging resources within defined architectural and security guardrails.

• Maintain clear technical documentation, READMEs, and operational procedures.

• Handle platform-level incident, problem, and change management.

• Collaborate closely with Security, Architecture, Infrastructure, and Software Development teams.
  

Requirements:

Kafka & Platform Engineering

• 4–6 years of experience with Apache Kafka at platform/engineering level.

• Strong experience with Kafka clusters, performance tuning, security, and administration.

• Experience with Strimzi Operator and Kafka on Kubernetes.

• Experience with Kafka Connect API.

• Knowledge of Kafka KRaft architecture.

• Experience with HiveMQ or enterprise MQTT platforms.

• Strong understanding of Kafka availability, replication, partitioning, retention, and scaling.

Development

• 4–6 years of experience with Java and Spring Boot.

• Experience developing or maintaining Kafka integrations and custom connectors.

• Experience with PostgreSQL.

Cloud & Kubernetes

• Strong experience with Azure Kubernetes Service (AKS).

• Solid Kubernetes administration and troubleshooting experience.

• Experience working with Linux, including WSL.

• Experience with Azure and/or other major cloud platforms.

DevOps & Automation

• Strong experience with GitHub Actions and/or Jenkins.

• Experience with ArgoCD and GitOps practices.

• Strong Infrastructure as Code experience using Terraform or equivalent.

• Experience with Helm and OCI-based artifact management.

• Experience with automated deployment and platform lifecycle management.

Observability

• Experience with Prometheus and Grafana.

• Experience with Splunk.

• Knowledge of Fluent Bit and/or OpenTelemetry.

• Experience creating dashboards, alerts, and operational monitoring for production platforms.

Nice to Have

• Experience with API Management (APIM) platforms.

• Experience across Azure, AWS, and/or Google Cloud.

• Experience with cloud cost optimization and resource efficiency.

• Experience working within large enterprise integration or platform engineering departments.

• Experience with Envoy Gateway or similar edge-routing technologies.

• Experience with KEDA and event-driven autoscaling.

• Experience with OAuth/OIDC-based authentication and API security.

What We Offer:

• A dynamic and innovative workplace driving advancements in cutting-edge robotic technologies

• The opportunity to collaborate with talented cross-functional teams on meaningful and impactful projects

• Competitive compensation and comprehensive benefits package

• A supportive culture that fosters continuous learning, growth, and professional development

• Flexible hybrid working model for an optimal work-life balance

• 25 days of annual leave to recharge and relax

• An annual wellness allowance of 3,500 SEK to support your health and wellbeing