Senior Server Engineer - Performance

Role overview Build and improve the systems that help backend teams understand how their services perform under realistic production conditions. You will define performance and reliability expectations, create ways to test them at scale, and help teams find and fix bottlenecks before they affect players. The role combines hands-on engineering with cross-team guidance on testing, observability, and resilient service design.

Responsibilities - Develop systems and strategies to assess backend performance, scalability, and reliability in a cloud environment. - Set service-level expectations for latency, throughput, and errors, then validate them under realistic conditions. - Build tools that simulate production traffic, high concurrency, interactions between services, and network variability. - Maintain load, stress, and endurance tests and integrate them into delivery pipelines to catch regressions early. - Use metrics, logs, and distributed tracing to identify bottlenecks and guide improvements. - Establish testing practices across services and work with feature teams on resilience and scalable design.

Requirements - Significant software engineering experience with backend or distributed systems in public cloud environments. - Experience building or operating highly available, scalable systems, such as real-time services or large-scale online games. - Strong Python skills, including asynchronous programming, concurrency, and performance considerations. - Understanding of service communication, event-driven systems, failure modes, resilience, and stateful versus stateless design. - Experience designing low-latency systems, using data stores such as Redis or DynamoDB, and building REST or gRPC APIs. - Familiarity with AWS, Docker, CI/CD, automated testing, infrastructure automation, and observability tools. - Hands-on experience with AI-assisted development tools and workflows.

Nice to have - Experience with load-testing tools such as k6 or Locust. - Familiarity with site reliability engineering practices.

Benefits and work setup The role is based in Barcelona with a hybrid arrangement, or remote from the UK, Ireland, Portugal, or elsewhere in Spain. Visa sponsorship may be available.