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).

• 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.

Nice-to-have

• 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.

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Why you’ll love working here:

Benefits Cafeteria — annual budget you allocate to:

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

Work-life & support

• 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.

Our culture & core values:

GR8_TECH culture is how we win — through trust, ownership, and a growth mindset. We move fast, stay curious, and keep it real, with open feedback, room to experiment, and a team that’s got your back.

FUELLED BY TRUST: we’re open, honest, and have each other’s backs.

OWN YOUR GAME: we take initiative and own what we do.

ACCELER8: we move fast, focus smart, and keep it simple.

CHALLENGE ACCEPTED: we grow through challenges and stay curious.

BULLETPROOF: we’re resilient, ready, and always have a plan.