Mid-Level Java API Developer – Cloud-Native Backend Services

Unleash the power of modern development — drive innovation through scalable API solutions!

Krakow-based opportunity with hybrid work model.

As a Mid-Level Java API Developer, you will be working for our client, a leader in digital banking services. You will design, build, and run secure, scalable APIs that support HSBC’s digital products and internal platforms. Collaborating within a cross-functional engineering team, you'll enable reliable services using cutting-edge Java and cloud-native architecture, including event-driven patterns. This role offers an exciting chance to contribute to financial technology innovation and advance your career in a dynamic environment.

Your main responsibilities:

• Build and evolve high-performing, scalable APIs and backend services using Java, Spring Boot, Maven, primarily in IntelliJ
• Collaborate with engineers, product owners, architects, and testers to deliver well-designed services aligned with business goals
• Design APIs following industry standards and patterns (e.g., REST, GraphQL, SOAP), ensuring versioning and backward compatibility
• Integrate with third-party and internal APIs, focusing on resilience, observability, and error handling
• Develop and support event-driven services using Kafka, including topic design, schema evolution, and message reliability
• Build cloud-ready services on AWS platforms such as Kubernetes/EKS, Fargate, Redis, RDS, S3, and Route 53
• Write automated tests, perform API testing, troubleshoot production issues, and contribute to continuous quality improvements
• Maintain clear API documentation (OpenAPI/Swagger) and create runbooks as needed
• Contribute to engineering standards focused on security, performance, and maintainability

You're ideal for this role if you have:

• At least 4 years of experience building APIs and backend services in Java
• Strong experience with Spring Boot and Maven development tooling
• In-depth understanding of backend architecture, including service design, data access, caching, and resilience patterns
• Knowledge of API standards such as REST, GraphQL, and SOAP
• Familiarity with API tooling like Postman, Swagger UI/OpenAPI, SoapUI
• Comfort working with JSON and XML data formats
• Proven ability to diagnose issues, fix defects, and enhance system reliability
• Excellent collaboration skills and clear technical communication

It is a strong plus if you have: (optional)

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

Language Required for the role:

• Good command of English (Communicative level)

Eligibility for the role:

• Only candidates with an existing legal right to work in the European Union will be considered for this role.

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Interested? Apply now and include your CV (preferably in English) along with a statement confirming your consent to the processing and storage of your personal data.