Software Engineer Java Kotlin Scala w Warszawa, Polska

Contract: B2B, 6 months + extensions Workload: full-time, 100% remote Language: English (fluent) Other: Occasional participation in an on-call rotation for the production platform. We are looking for highly skilled Senior Software Engineers to join an international engineering team building a production-grade financial technology platform used by leading financial institutions. The platform supports complex, real-time financial transactions and combines modern JVM technologies with distributed systems and Distributed Ledger Technology. Technology environment The platform uses technologies including: Java / JVM, Kotlin, Spring Boot. ActiveMQ and message-driven architectures. Gradle, Docker, Kubernetes, Ansible. Relational databases. APIs and external system integrations. Canton / Daml and Distributed Ledger Technology. SWIFT-based financial integrations. Kotlin experience is welcome but not required – strong Java/JVM engineers can learn it within the project. What you will do Design and develop core components of a highly transactional financial platform. Implement complex business logic and workflows. Build resilient, secure and maintainable JVM services. Work with message-driven and distributed architectures. Develop integrations using APIs, messaging and financial communication protocols. Contribute to Distributed Ledger components and workflows. Solve complex concurrency, data consistency and transactional problems. Participate in architectural assessments and threat-modelling sessions. Collaborate with experienced Developers, DevOps Engineers and QA Engineers across several countries. Contribute to code reviews and technical design discussions. Support a production-grade system and occasionally participate in the on-call rotation. Ensure high standards of correctness, security, resilience, confidentiality and operational stability. What we are looking for Ideally 6+ years of professional Software Engineering experience. Very strong commercial experience with Java and the JVM ecosystem. Excellent understanding of core Computer Science concepts. Strong knowledge of object-oriented software design and engineering principles. Experience building complex, production-grade backend systems. Understanding of databases and transactional systems. Experience with concurrency and multithreading. Knowledge of message-driven or event-driven architectures. Strong analytical and problem-solving skills. A Master's degree in Computer Science or a closely related technical field is strongly preferred. Recruitment process Please note that the technical bar for this team is high. The recruitment process is designed to assess both practical coding ability and strong Computer Science fundamentals: Online technical assessment completed at home. 30-minute technical screening with coding and technical questions. Technical interview including live coding. Second technical interview including further live coding and technical assessment. Final soft-skills interview. The full process is expected to be completed within approximately two weeks.