Senior Backend Developer

About Next LevelNext Level is a Georgian iGaming studio that designs, builds, and operates its own online casino games and supporting technology. The company creates crash games, mini-games, slots, and peer-to-peer skill games such as Backgammon, Domino, card games, etc. These games are delivered to online casinos through an end-to-end platform covering game clients and servers, player authentication, wallets, operator integrations, promotions, tournaments, admin tools, and analytics. Next Level combines game development, product design, visual art, animation, and platform engineering within one closely connected team. It owns the full process - from game concept and visual identity to development, deployment, and production operation. The RoleYou will design, build and run backend services where correctness is money. Bets, wins, cancellations and bonuses flow through your code in multiple currencies, under concurrency, for players who notice a missing cent within seconds. The work spans two halves of our backend: real-time game servers (round loops, player sessions, game math) and the platform services around them (wallet, authentication, operator integrations, promotions, tournaments, reporting). What You Will Do1. Own services end-to-end: API design, domain model, database migrations, deployment, and the first weeks in production. 2. Build new games and game modes on our shared game-server foundations. 3. Make the money path boring: idempotent transaction flows, explicit ledger states, precise decimal arithmetic, and tests that reproduce the race instead of hoping it will not happen. 4. Integrate new casino operators: secure wallet APIs, token exchange and game-launch flows. 5. Design for horizontal scale: stateless services, shared state in the right store, asynchronous messaging between services. 6. Raise the engineering bar through code review, conventions, test coverage and observability. 7. Work closely with frontend engineers on real-time contracts and with the platform team on deployments and releases. Our Stack8. C# on modern .NET, ASP.NET Core, Clean Architecture with CQRS-style request handling. 9. PostgreSQL (EF Core, with raw SQL where it matters), Redis, a message broker for cross-service events, and a columnar analytics database. 10. SignalR / WebSockets for real-time gameplay. 11. JWT authentication, signed operator APIs, rate limiting, and resilience policies. 12. xUnit-based testing, including dedicated concurrency and load tests. 13. Docker, Kubernetes, GitLab CI, and GitOps-based deployments. What We Are Looking For14. 5+ years building production backends in C#/.NET, including several years on ASP.NET Core in a multi-service system. 15. Deep, practical PostgreSQL: schema design, migrations on live data, indexing, transactions and isolation levels. 16. Real experience with message brokers and distributed caches - including their failure modes: duplicates, ordering, reconnects, stampedes. 17. Concurrency fluency: locks vs. optimistic concurrency vs. database constraints, idempotency, services that scale out without shared memory. 18. You have shipped and operated real-time or high-throughput systems (gaming, betting, trading, payments) and can reason about latency budgets. 19. Strong testing instincts: you test the race, not just the happy path, and can explain what you did not test and why. 20. Comfortable owning deployment: containers, Kubernetes basics, reading pipeline output, rolling back. 21. Clear written English - our documentation, reviews and commit history are in English. Nice to Have22. iGaming, betting or payments background: wallet APIs, operator integrations, RNG and RTP, provably-fair schemes, certified game math. 23. Event sourcing or CQRS at scale; building analytics pipelines. 24. Infrastructure-as-code, GitOps, API gateways, or background job schedulers. 25. Effective, responsible use of AI coding assistants. How We Work26. Small team, direct communication, no ticket factories. You talk to the people deploying the code and the people designing the games. 27. Written conventions, merge-request reviews, and staged environments from development to production. Hiring Process28. 30-minute intro call. 29. Technical deep-dive (90 min): walk us through a system you built; we will dig into concurrency, money handling and data design. 30. We may ask you to complete a short test task relevant to the role. 31. Conversation with the founders. How to ApplySend a CV or a link to work you are proud of to careers@nextlevelteam.io