Senior API Developer – Java and Cloud-Native Architecture

Our requirements

• 5+ years of experience building APIs and backend services in Java.
• Strong expertise with Spring Boot and build tools like Maven.
• Deep understanding of backend architecture concepts such as service design, data access, caching, and resilience.
• Proven experience with API architectural styles (REST, GraphQL, SOAP) and integration patterns.
• Hands-on experience with API tooling (Postman, Swagger UI/OpenAPI, SoapUI).
• Proficiency working with data formats like JSON, XML, XAML.
• A track record of diagnosing issues, fixing defects, and enhancing system performance and reliability.
• Excellent collaboration skills and the ability to communicate complex technical ideas clearly.
• Fluent English command (spoken and written).
• Only candidates with an existing legal right to work in the European Union will be considered for this role.

Optional

• Experience with event-driven architecture at scale (Kafka streams, schema registry, idempotency, exactly-once/at-least-once patterns).
• Background building and operating services on AWS (Kubernetes/EKS, Fargate, Redis, RDS, S3, Route 53).
• Familiarity with CI/CD pipelines, observability tools (logging, metrics, tracing), and secure coding practices.
• Strong critical thinking with a pragmatic, delivery-focused mindset.

Your responsibilities

• Build and evolve high-performing, scalable APIs and backend services using Java, Spring Boot, Maven, primarily within IntelliJ.
• Collaborate effectively with cross-functional teams—including engineers, product owners, architects, and testers—to deliver reliable services aligned with business objectives.
• Design APIs following established standards (REST, GraphQL, SOAP) with attention to versioning, backward compatibility, and user experience.
• Integrate with third-party and internal APIs, ensuring system resilience, observability, and robust error handling.
• Develop and support event-driven services using Kafka, including schema evolution, topic design, and message reliability patterns.
• Build cloud-ready services on AWS, considering deployment and runtime aspects for Kubernetes/EKS, Fargate, Redis, RDS, S3, and Route 53.
• Own quality assurance by writing automated tests, conducting API testing, and troubleshooting production issues, embracing a “you build it, you run it” mindset.
• Produce and maintain clear API documentation (OpenAPI/Swagger) and operational runbooks where needed.
• Contribute to engineering standards emphasizing security-by-design, performance, and maintainability, driving continuous improvement.

About the project

This is how we organize our work

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What we offer

• Stable and long-term cooperation with very good conditions
• Enhance your skills and develop your expertise in the financial industry
• Work on the most strategic projects available in the market
• Define your career roadmap and develop yourself in the best and fastest possible way by delivering strategic projects for different clients of ITDS over several years
• Participate in Social Events, training, and work in an international environment
• Access to attractive Medical Package
• Access to Multisport Program
• Access to Pluralsight
• Flexible hours

Benefits

• sharing the costs of sports activities
• private medical care
• flexible working time
• fruits
• integration events
• corporate gym
• saving & investment scheme
• no dress code
• coffee / tea
• drinks
• christmas gifts
• birthday celebration
• sharing the costs of a streaming platform subscription
• access to +100 projects
• access to Pluralsight

Recruitment stages

• 1.
  first online interview
• 2.
  second online interview

ITDS Polska Sp. z o.o.