Senior Programmer, Engine Reliability in Harrow

Our engine, Titan, powers some of the highest-grossing games in mobile – titles that have generated billions in revenue and reach hundreds of millions of players. We are investing heavily into the future of Titan, and as part of that investment we’re building a brand-new Reliability team: an autonomous, high-skill group that will work alongside our engine teams, empowering them to work safer, faster, and easier through better infrastructure, automation, and feedback loops. The role that Reliability plays is crucial to the success of Titan’s future.

As agentic workflows become more common the pace of iteration rises, and confidence in what we ship becomes the bottleneck. We see this team as a strategic bet in solving that problem — building the validation surfaces, automation, and reliability loops that help our engine teams move faster without increasing risk to what matters most – our games and players. This is an AI-forward engineering team by design. We are not treating AI as a side tool; we are building around the reality that modern engineering will increasingly depend on AI-assisted workflows for validation, automation, and test generation — with strong engineering judgment and clear guardrails.

This role is client-leaning, focused on the engine and runtime: C++, mobile platforms, runtime behaviour, performance, and the practical challenges of validating shared engine changes before they reach games.

What You’ll Be Doing

• Build & evolve automated reliability foundations: including validation workflows, regression detection, integration stability, and performance/stability signals.
• Establish and grow realistic end-to-end validation surfaces across real devices and real services, so issues are caught before they reach games.
• Improve how shared engine changes are validated against real game integrations, reducing manual pain and making confidence more repeatable.
• Create and maintain tooling, infrastructure, and test surfaces that engine and horizontal teams can rely on.
• Partner with client, server, and live-ops teams to make systems testable and reduce surprises.
• Apply modern AI-assisted workflows to validation, automation, and test generation in pragmatic, well-guardrailed ways.
• Contribute directly to priority technical work where improving testability or validation unlocks broader reliability gains.

What You Have

• Strong professional experience in modern C++.
• Engine/runtime development experience, with comfort debugging complex cross-platform issues across platforms such as iOS, Android, macOS, or Windows.
• Strong instincts around testing and validation strategy: you understand the trade-offs between unit, integration, and end-to-end testing, and where each creates the most value.
• Experience with build systems, automation, and developer tooling such as CMake, CI pipelines, and scripting.
• Strong collaboration skills and the ability to work effectively across teams without adding unnecessary process overhead.
• Interest in AI-assisted engineering workflows, with good judgment about where they add leverage and where they need guardrails.
• Comfort operating in an ambiguous space and helping shape a new team’s practices as it grows.

Would Be Nice if You Also Have

• Experience with device automation, device farms, or test frameworks such as Catch2 or gTest.
• Experience with observability and debugging tools such as Sentry, logs, metrics, tracing, or dashboards.
• Experience improving testability, validation, or reliability in shared engine or platform code.
• Experience working across client and backend workflows, even if your main background is client-side.
• Hands-on experience using AI-assisted development tools as part of day-to-day engineering work.

Where You’ll Be

You can be located either in London or Helsinki.

About Supercell

Supercell is a games company from Helsinki, Finland, with offices also in San Francisco, Seoul, Shanghai, and London. You might know us as the makers of Hay Day, Clash of Clans, Boom Beach, Clash Royale, and Brawl Stars. Our mission is to create great games that as many people as possible play for years and that are remembered forever. So, how do we make great games? By putting together the best teams and giving them the freedom and independence to succeed. And by taking risks, failing, sharing learnings, and killing lots of projects.

Hey, You Might Love It Here!

Independent cells and trust are at the core of our culture. But it takes more than that to make great games. We take good care of our people, providing them with the compensation, work environment, and resources they need to succeed while having fun along the way.

You Are Not Your Job Title ™

Here, you won’t need to focus on chasing titles or climbing ladders. Internally, our job titles don’t include prefixes like Senior, Junior, Principal, or Director. Recognition isn’t tied to your title, as it doesn't define the impact you can have around here.

Benefits And Compensation

Luring you in with glitter, glamour, and gems isn't what we're about. We want you to enjoy your time here fully, so we structure our compensation and benefits with that in mind. It starts with perceiving you as a human being, not a resource.

Relocation?

Yes! No matter where you’re moving from, our dedicated mobility team and partners will support you throughout your move. We’ll ensure the process is as smooth as possible for you and anyone joining you – whether they’re family members of the human or animal kind!

Not Sure if You Should Apply?

Many candidates with great skills and experience second-guess themselves. The bar is high, but if this role excites you, apply! We’re here to help you succeed. Also, we're happy to learn about any specific accommodations you may need to fully engage in our recruitment process.

Wishing you all the best, The Supercell Recruitment team.