Senior Backend Software Engineer (m/w/d)

<h3>Tech stack you’ll work with</h3> <ul><li>Core: Golang, AWS Serverless (Lambda, API Gateway, SQS)</li><li>Data: DynamoDB, PostgreSQL</li><li>Messaging: Kafka</li><li>Ops / Tooling: Terraform, Gitlab Actions (CI/CD)</li></ul>(If you haven’t touched every tool yet, no worries — we’ll get you up to speed.) <h3>Deine Aufgaben und Verantwortlichkeiten</h3> <ul><li>Implement new micro-services and extend existing ones in Go.</li><li>Help groom user-story requirements and surface performance / scaling concerns early.</li><li>Write unit, integration and API tests; review PRs.</li><li>Tune data-models in DynamoDB &amp; Postgres for low-latency, high-throughput workloads.</li><li>Pair with DevOps on CI/CD and observability improvements.</li><li>Participate in on-call rotation as we’re building high available fintech system</li><li>Design and drive high-scale, low-latency services (tens of thousands of orders / sec).</li><li>Lead architecture reviews, challenge assumptions and keep tech debt in check.</li><li>Partner with Product on roadmap feasibility &amp; effort sizing.</li><li>Be a mentor to less experienced colleagues.</li></ul> <h3>Deine Qualifikationen und Erfahrungen</h3> <ul><li>~3 years of professional back-end experience (ideally 1 year+ in Go).</li><li>Solid grasp of cloud-native design (RESTful APIs, event-driven patterns).</li><li>Working SQL and NoSQL skills; know when each shines.</li><li>Comfort diagnosing performance bottlenecks in distributed systems.</li><li>Ability to work on-site in Warsaw twice a week (Tue &amp; Thu) and remotely otherwise.</li></ul> <h3>Nice to have</h3> <ul><li>Exposure to serverless architectures on AWS.</li><li>Experience with Kafka or another high-volume message bus.</li><li>Knowledge of automated trading, market data, or FIX/crypto exchanges.</li><li>Familiarity with Infrastructure-as-Code (Terraform or CDK).</li></ul> <h3>Vertragsart</h3> <p>B2B / Employment contract</p> <h3>Location</h3> <p>Hybrid (Warsaw – in-office every Tuesday &amp; Thursday)</p> <h3>Warum wir?</h3> <p>What We Offer:</p><ul><li><p>An experienced, welcoming team that loves clean, well-tested code.</p></li><li><p>Real impact: the features you ship go straight into production for live traders.</p></li><li><p>Flexible hours, modern tooling, and a fintech domain that’s never boring.</p></li><li><p>Occasional work travel to Germany (Munich / Berlin)</p></li><li><p>20 days PTO on B2B</p></li><li><p>Multisport card</p></li></ul> <h3>Jetzt bewerben!</h3> <p>Apply now!</p>