Senior API Engineer

We are seeking a Senior API Engineer who will design, develop, and maintain robust, well-tested APIs that enable customers and partners to integrate quickly and securely with our systems.

Key responsibilities

• Build microservices and SDKs in Python, Java, or Go as required by each domain.

• Refactor existing APIs to improve performance, maintainability, and developer experience (DX).

• Automate unit, contract, and integration tests (pytest, JUnit, Go testing, Postman/Newman).

• Implement CI/CD pipelines (GitHub Actions, Jenkins, GitLab CI) and deployments on Kubernetes.

• Instrument logs, metrics, and distributed traces (OpenTelemetry, Prometheus, Grafana).

• Take part in code reviews, standards definition, and documentation (Markdown, Swagger-UI).

• Collaborate closely with Frontend, DevOps, and Product Managers to deliver continuous business value.

Technical requirements

• 5+ years developing production APIs and microservices.

• Hands-on experience in at least two of these languages: Python, Java, Go.

• Strong understanding of HTTP, REST, semantic versioning, error handling, and security (JWT, mTLS).

• Solid experience with relational and NoSQL databases (PostgreSQL, Redis, MongoDB).

• Proven track record of automated testing and high code coverage.

Key competencies

• Quality mindset and continuous-improvement orientation.

• Excellent debugging and troubleshooting skills.

• Teamwork and DevOps mentality.

Why Join Us?

• Flexible Remote Work

• B2B contract

• Possibility of using a coworking space in Cracow (with access to prosecco from a tap and a billiard table ;))

• Private medical care package and Multisport card

• Quarterly integration events

• Positive atmosphere created by our super team - open-minded, eager to help people who are truly committed to what they do and who build relationships based on mutual respect and good humor