Senior Full-Stack Developer (BE-Focused) — iGaming product

Hi 🙌

Umber is looking for a Senior Full-Stack developer with a strong backend focus to join us long-term and build an iGaming product from scratch for one of our key clients.

Where you’re joining

A small senior team at an early stage. Backend is currently carried by one strong engineer, so you’d be the second. That means a real domain of your own from week one, influence on architecture instead of inheriting someone else’s decisions, and room to grow your technical scope as the team grows. Decisions here take days, not sprints. AI tooling is a normal part of how we work, and we expect you to use it well and to own the quality of what ships either way.

We build mobile-first real-money games and the platform behind them, in-house, for one of our key clients, so they can grow a catalogue of their own instead of relying on external game providers. We own what makes a game run correctly and profitably: game sessions, integration with the client’s platform, analytics and experimentation, and the back-office it is all configured, tracked, and run from.

We’re pre-launch, and the first release to a real audience is close. From that point on we learn from how people actually play. What we build now has to hold when real players arrive, which is exactly why we want someone who has already run systems at scale rather than someone learning it here.

What you will do

• Build and scale the backend behind our games: live sessions, game state, and the services around them.
• Design and build new backend functionality as the product grows, owning features from architecture through to production rather than picking up work someone else has already designed.
• Own the integration layer between our games and the client’s platform, where correctness under retries and failures directly affects money.
• Build game configuration, versioning and release management for a growing catalogue of games.
• Design and tune PostgreSQL and event processing for high throughput (NestJS, NATS, gRPC).
• Build the analytics and experimentation foundation the product makes its decisions on.
• Bring proven iGaming architecture patterns and approaches to how we build, and raise the standard of what already exists.
• Pick up frontend work on the back-office when needed.
• Own a domain end-to-end, from architecture and implementation to production and incidents, as a peer to the rest of the senior team, and set the technical bar through review and mentoring.

What we’re looking for

• 7+ years building server-side systems, with substantial recent work in Node.js/NestJS and TypeScript.
• Hands-on iGaming experience. You know what makes real-money flows different from ordinary CRUD.
• Proven experience designing and operating high-load, data-intensive systems in production. You can name the load you carried and the bottleneck you hit.
• Deep PostgreSQL: schema design, query and index tuning, behaviour under write pressure.
• Microservices and async event processing done for real: failure modes, retries, backpressure, idempotency.
• Working React knowledge, enough to pick up frontend tasks on the back-office when needed. This is a backend-first role.
• You’ve been the person others bring design questions to, and you carry decisions to production without being managed.

Nice to have

• Experience taking a game or platform through certification, whether GLI/BMM or an audit in a licensed jurisdiction. Having been on the engineering side of that process is a strong plus for us.
• Experience integrating games with operator platforms or aggregators.
• Anti-fraud or bonus-abuse work in gambling.
• Go / Rust.
• Three.js or game-rendering experience.
• Experience with AWS/DO, Docker, and CI/CD.

Our tech stack

NestJS, Node.js, TypeScript, Go, Rust, NATS, gRPC, PostgreSQL, React, WebSocket, microservices, Docker, AWS, CI/CD, high-load architecture.

Hiring Process

• Pre-screening tech call with a Talent Sourcer (15–30 minutes).
• Intro call with a Talent Partner (60–75 minutes).
• Technical interview (~1.5 hours).
• Reference/Background check.
• Final call with the CTO (~45 minutes).
• Final decision and offer.

Terms

Full-time · Contract-based cooperation (FOP) · 3-month probation · 24 paid days off + New Year & Christmas · Fully remote from Ukraine or Europe, with overlap on CET working hours · No time trackers · Annual performance review.