EU remote
Senior Java Developer
About this role
GR8_TECH builds B2B iGaming platforms for operators who play to lead. We deliver full-cycle, high-impact tech designed to scale — from seamless integrations and expert consulting to long-term operational support. Our platform powers millions of active players and drives real business growth. Call it what it is: the iGaming Platform for Champions. With 1000+ GR8 people across locations and time zones, we don’t just ship technology — we help operators build success stories across brands, markets, and geos.
Our ambition drives us. Our people make it real. If you’re a challenger in spirit and a champion in action — join us. Why this role exists: This role exists to design, build, and maintain backend services across the Casino platform — bonus and promotional mechanics, wallet and transaction flows, game launch and catalog, and game provider integrations — ensuring reliability, correctness, and performance under high load.
What you’ll drive: Casino platform services Design and develop Spring Boot microservices across the casino domain: bonus processing, game launch, lobby and game catalog management. Implement and evolve promotional mechanics end-to-end — from bonus crediting and wagering logic to expiry and settlement — with correctness guarantees on real money. Integrate third-party game providers, game launch, wallet callbacks (bet/win/refund), provider-side bonus features.
Build and evolve REST APIs consumed by internal services and external providers, including request signing, authentication, and API versioning. Reliability & correctness Ensure correctness of real-money transaction and bonus flows — idempotency, retries, timeouts, graceful degradation of downstream calls. Work with Redis for caching and session state; tune service performance under production load. Own observability: metrics (Micrometer/Prometheus, Grafana dashboards), structured logging, alerting.
Quality & delivery Write and maintain unit, integration, and functional tests (JUnit 5, Testcontainers). Ship via GitLab CI to Kubernetes; participate in code review and incident investigation. What makes you a GR8 fit: Must-have 5+ years of experience in back end. Commercial experience with strong proficiency in Java (17+) and Spring Boot 3.x (Web, Security, Data, Actuator). Experience building business-critical domain logic (payments, bonuses, billing, or similar money-adjacent flows).