Senior Game Engineer

About Us

At Trailmix, our players are the very reason we exist and our mission is to create delightful spaces where millions of people can flourish. Our hit game Love & Pies, launched in September 2021, has resonated with millions worldwide and we build free-to-play mobile games that are snackable yet filled with heart, humour, and stories that stick

We’re a focused and highly collaborative team with a big creative spirit. We believe the best games are made when the people behind them feel inspired, supported, and proud of the work they do.

That’s why our values sit at the heart of how we work, shaping every decision and creative choice we make.

Trailmix Values

• We win as one: Success is shared, and collaboration fuels everything we do because great games are never built solo.
• We are resilient by nature: We adapt and rise stronger each time because every challenge is a chance to evolve.
• We are powered by our players: Every choice begins with them because when our players thrive, so do we.
• We are kind and direct:  We speak with honesty and care because clarity and compassion build the trust that makes us better.
• We stay curious and grow:  We ask, explore, and learn because curiosity keeps our creativity alive.
• We decide boldly and own fully: We move with courage and conviction because great ideas only matter when we stand behind them.

Our values are what set Trailmix apart: they guide us in crafting games that are joyful, authentic, and player-first. We've created a workplace where both people and players feel seen, supported, and inspired.  If you’re excited by meaningful creativity, true collaboration, and making games that bring people joy, you’ll feel right at home here, too.

The Opportunity

As a Senior Game Engineer, you will be reporting to the Engineering Lead. You’ll be responsible for both accelerating developer productivity and platform reliability and delivering high-impact player features across our mobile titles. You will partner with gameplay and content teams to remove friction, raise quality bars, and shorten time-to-ship. You will also own end-to-end implementation of player-facing features in Unity, from scoping and technical design through development, testing, release, and post-launch iteration.

The Day to Day

• Deliver features end-to-end with craft: scopes clearly, communicates trade-offs, and lands quality on time, then iterates from data.
• Own build/CI/CD pipelines and release automation (caching, test gates, artifact/versioning, rollback paths).
• Lead Unity project architecture, shared packages/modules, and upgrade strategies.
• Establish standards for telemetry, profiling, and performance budgets; drive regression detection.
• Implement feature flags/remote config patterns and experimentation hooks.
• Improve environment management (secrets/provisioning, sandbox/staging parity, config as code).
• Define and evangelise technical standards, branching/PR conventions, and code review guidelines; author runbooks and docs.
• Create developer tooling (scaffolds/CLIs/templates) to speed feature delivery and reduce toil.
• Build robust gameplay architectures (state machines, animation controllers, input, tooling) that balance iteration speed with long-term maintainability.
• Implement gameplay features and UI flows in Unity/C#, collaborating with Design, Product, Content, and QA to ship high-quality player experiences.
• Own the feature lifecycle: technical design, estimation, task breakdown, implementation, code review, test coverage, and live rollout.
• Instrument features for data, events, and A/B tests; define success metrics and partner with Data to validate outcomes.
• Maintain performance budgets for new features (memory, CPU/GPU, load times) and proactively profile/optimise.
• Harden features for LiveOps: remote config/feature flags, safe fallbacks, and rollback paths.
• Triage, fix, and iterate on live feature issues using observability dashboards and player feedback.

About You

• Senior-level Unity/C# experience delivering complex features and shared systems at scale.
• Proven track record shipping player-facing features in live mobile games (end-to-end ownership).
• Strong Unity skills across UI/UX flows, scene/prefab architecture, and gameplay systems (e.g., state, animation, content pipelines).
• Comfortable defining acceptance criteria, writing unit/integration tests, and partnering with QA on test plans.
• Demonstrable expertise in CI/CD for mobile, package/SDK management, and release automation.
• Strong grasp of telemetry, performance tooling, and reliability engineering within game teams.
• Excellent communication and mentoring skills; proven cross-disciplinary collaboration.

Bonus

• Experience designing and running A/B tests and telemetry for feature validation.
• Background in F2P feature implementation (progression systems, economies, events, or narrative delivery).
• Experience with Kubernetes/GKE build farms, PlayFab/Metaplay SDKs, and mobile store pipelines.

At Trailmix, we care as much about how you work as what you deliver. We believe that when people feel safe, inspired, and proud of what they do  that passion flows directly into our games and ultimately our players feel it.

That means we’re looking for someone who:

• Builds impact through collaboration: You know the best work comes from shared perspectives and collective wins.
• Grows stronger through challenges: You adapt, stay positive, and help others find a way forward when things get messy.
• Keeps players at the heart of decisions: You design, create, and problem-solve with empathy, knowing players are our why.
• Communicates with clarity and care: You give feedback that builds trust, and you listen openly so ideas can flourish.
• Stays curious and lifts others up: You experiment, learn quickly, and share your discoveries generously, raising the bar for the whole team.
• Moves with courage and ownership: You make bold calls when it matters, and you stand by them with accountability.

Why Trailmix?

As a member of our team, you’ll work in an environment where collaboration and creative energy drive everything we do. We believe that working closely with colleagues from across departments is essential to crafting the best experiences for our players. Our office is a place where ideas come together, and we work side by side to turn them into reality.

Our London Studio Location

Our hybrid work model combines the flexibility of remote work with the creative energy of being together in person.

We work from our Kings Cross studio together three days a week — Monday, Thursday, and Friday, because we believe great games (and great teams) are built through genuine collaboration.

These days are focused, energised, and designed for impact:

• We solve problems faster
• We share ideas in the moment
• We drive decisions that move us forward

This rhythm helps us deliver our best work not just for each other, but for our players. It’s how we build momentum, grow together, and stay ahead in a fast-moving industry.

Our Benefits

• Investing in Your Growth: Unleash your potential with our generous development budget. After completing your three-month probation, all team members receive a £1,000 allowance to fuel their professional growth each year.
• Fueling Your Day: Our kitchens are fully stocked with delicious treats and drinks, and we provide breakfast and lunch supplies to keep you energised throughout the day.
• Building Connections: Join us every Friday for a team lunch courtesy of Just Eat -  a chance to connect and recharge for the week ahead.
• Planning for Your Future: Take control of your financial future with our contributory pension scheme. Plus, enjoy the added benefit of tax-free contributions.
• Unlocking Ownership: As a valued team member, you'll have the opportunity to own a stake in our success through tax-advantaged stock options.
• Caring for Your Wellbeing: Your health is our priority. Enjoy peace of mind with our fully comprehensive private medical care, with premiums paid by Trailmix. Plus, access mental health support 24/7 with the Spill Mental Health App.
• Time to Recharge: Our generous holiday allowance allows you to take a well-deserved break. You'll enjoy 28 days of annual leave, including three company holiday days around Christmas.
• Surprise and Delight: Feel appreciated and valued with various company gifts throughout the year.
• Celebrations: Join us for various socials and events throughout the year, from team outings to themed parties.
• Setting You Up for Success: Receive a £250 work-from-home budget to ensure you have the proper home setup to perform at your best.

Our Inclusive Culture

Trailmix was founded to make a positive impact on our players, our community, and our colleagues. We’re committed to creating an inclusive culture where everyone can flourish and feel seen.

We believe it’s vital that players see themselves represented in the games they play; and in Love & Pies, we celebrate the beautiful diversity of life. The stories, characters, and relationships in our games reflect the people we are and the people we love.

We’re always excited to welcome more people who share our passion for designing games that truly include everyone.