Senior or Mid Backend Software Engineer (m/f/d)

• Core: Golang, AWS Serverless (Lambda, API Gateway, SQS)
• Data: DynamoDB, PostgreSQL
• Messaging: Kafka
• Ops / Tooling: Terraform, Guthub Actions (CI/CD)

Mid Backend Software Engineer

• Implement new micro-services and extend existing ones in Go.

• Help groom user-story requirements and surface performance / scaling concerns early.

• Write unit, integration and API tests; review PRs.

• Tune data-models in DynamoDB & Postgres for low-latency, high-throughput workloads.

• Pair with DevOps on CI/CD and observability improvements.

• Participate in on-call rotation as we’re building high available fintech system

Additional tasks of the Senior

• Design and drive high-scale, low-latency services (tens of thousands of orders / sec).
• Lead architecture reviews, challenge assumptions and keep tech debt in check.
• Partner with Product on roadmap feasibility & effort sizing.
• Be a mentor to less experienced colleagues

• 3+ years of professional back-end experience (ideally 1 year+ in Go).

• Solid grasp of cloud-native design (RESTful APIs, event-driven patterns).

• Working SQL and NoSQL skills; know when each shines.

• Comfort diagnosing performance bottlenecks in distributed systems.

• Ability to work on-site in Warsaw twice a week (Tue & Thu) and remotely otherwise.

• Exposure to serverless architectures on AWS.

• Experience with Kafka or another high-volume message bus.

• Knowledge of automated trading, market data, or FIX/crypto exchanges.

• Familiarity with Infrastructure-as-Code (Terraform or CDK).

What We Offer:

• An experienced, welcoming team that loves clean, well-tested code.

• Real impact: the features you ship go straight into production for live traders.

• Flexible hours, modern tooling, and a fintech domain that’s never boring.

• Occasional work travel to Germany (Munich / Berlin)

• 20 days PTO on B2B

• Multisport card