We are looking for an experienced Site Reliability Engineer to ensure the stability, scalability, and operational excellence of a Kubernetes\-based platform running in a hybrid environment. The project is entering a pivotal phase, with a major go\-live planned for mid\-February and a target audience of 75,000 users. User onboarding is already underway, with over 5,000 users connected and 15,000–20,000 expected to be active by year\-end. While the system is stable, we anticipate increased activity and new challenges in January, February, and after the go\-live—making this an exciting opportunity to make a real impact. The role focuses on performance optimization, scaling strategies, observability, and reliability engineering. **Required Skills:** * 4\+ years of experience as SRE / DevOps Engineer * Strong hands\-on experience with Kubernetes in production * Experience working with hybrid infrastructure (on\-prem \+ cloud) * Solid knowledge of PostgreSQL performance tuning and scaling * Experience with Qdrant or other vector databases * Experience with Helm, Kubernetes autoscaling, and resource optimization * Familiarity with observability stacks (Prometheus, Grafana, ELK/Loki) * Understanding of performance engineering and load testing * Experience with Linux systems and networking * Strong troubleshooting and incident\-management skills **Nice to Have:** * Experience with STACKIT or other sovereign clouds * Experience with PgBouncer * Knowledge of SRE practices (SLO/SLI) * Experience in regulated or public\-sector environments * German language skills **Responsibilities:** * Operate and optimize hybrid infrastructure (on\-prem \& STACKIT) * Manage and scale Kubernetes clusters * Optimize Helm charts, resource usage, and autoscaling * Conduct performance, load, and stress testing * Ensure reliability, availability, and monitoring of production systems * Tune and operate PostgreSQL * Operate and optimize vector databases (e.g. Qdrant) * Implement monitoring, logging, and alerting * Support incident response and capacity planning **We offer\*:** * Flexible working format \- remote, office\-based or flexible * A competitive salary and good compensation package * Personalized career growth * Professional development tools (mentorship program, tech talks and trainings, centers of excellence, and more) * Active tech communities with regular knowledge sharing * Education reimbursement * Memorable anniversary presents * Corporate events and team buildings * Other location\-specific benefits * not applicable for freelancers