Senior Java Developer

📍 Warsaw (Onsite – near Metro Plac Wilsona) 💼 B2B / Freelance About Silk Software House Silk Software House builds and maintains mission-critical backend systems for fintech, payments, and large-scale platforms. We value strong engineering judgment, ownership, and long-term cooperation over short-term delivery pressure. Your Role As a Senior Java Developer, you’ll take technical ownership of backend services, influence architectural decisions, and mentor other engineers. You’ll work directly on complex domains where performance, security, and reliability matter. Responsibilities Design and implement backend architectures using Java 11+ and Spring Lead development of microservices and APIs Optimize performance, scalability, and data consistency Work deeply with Hibernate , transactions, and database internals Review code, mentor developers, and set engineering standards Collaborate with DevOps on deployments and observability Requirements This role requires full-time onsite work (no remote or hybrid options). Candidates must be willing and able to work from our office near the Plac Wilsona metro station 5+ years of commercial experience as a Java Developer Strong commercial experience with Java & Spring (Boot, Security, Data) Deep knowledge of Hibernate ORM , SQL databases, and JVM behavior Experience designing scalable, maintainable backend architectures Proficiency with CI/CD, Git, Gradle, and production debugging Effective use of AI-assisted development tools ( ChatGPT, Claude, Cursor, Grok ) English at B2+ level Nice to Have Event-driven architecture (Kafka, queues) Cloud-native systems (AWS/GCP/Azure) Kubernetes, Docker, observability tools Experience in fintech or high-traffic systems Rates (B2B) 120–160 PLN / hour Recruitment Process Intro call (30 min) Senior-level technical interview Architecture & project discussion Offer Tech Stack Java: Advanced Spring Boot: Advanced Hibernate: Advanced PostgreSQL: Advanced Solid: Advanced DDD: Advanced REST API: Advanced