Senior Java Developer

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.

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.

• 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.

• 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.

• Write and maintain unit, integration, and functional tests (JUnit 5, Testcontainers).
• Ship via GitLab CI to Kubernetes; participate in code review and incident investigation.

• 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).
• Solid experience integrating third-party REST APIs and designing your own.
• Understanding of distributed systems basics: idempotency, consistency, timeouts, retries, caching.
• Experience with SQL and at least one NoSQL store (Redis, Cassandra, or Elasticsearch).
• Upper-intermediate or higher level of English.

• Scala experience (parts of our wallet platform run on Scala / Play / Akka).
• Experience with Kafka and event-driven architectures (some of our services use Spring Cloud Stream).
• Experience running services on Kubernetes; familiarity with GitLab CI.
• Familiarity with Prometheus and Grafana.
• iGaming / betting domain experience.

Benefits Cafeteria - annual budget you allocate to:

Sports • Medical • Mental health • Home office • Languages.

• Paid maternity/paternity leave + monthly childcare allowance.
• 20+ vacation days, unlimited sick leave, emergency time off.
• Remote-first + tech support + coworking compensation.
• Team events (online/offline/offsite).
• Learning culture with internal courses + growth programs.