Please note that this is a hybrid position based in Cardiff, requiring 3 days onsite each week, with the option for remote work on the remaining days.

Part of the Rocket Science Group, Atomic Theory comprises a multinational team of seasoned AAA veterans with roots extending from Blizzard, PUBG, Epic, and Unity. We have a track record of delivering player-centric, AAA-quality experiences, and we're unwavering in our commitment to performance, accessibility, and the meticulous attention to the engineering tools and frameworks that underpin exceptional gameplay.

But Atomic Theory is also more than just a studio; for us, it's a sanctuary, a place where our diverse experiences can intersect and combine to carry our solutions to the next level. We're dedicated to aiding studios and publishers in navigating the toughest challenges across today's game development landscape - and with offices in Albany NY, Brighton UK and Cardiff UK, we thrive at the opportunity to Get Sh!t Done on a global scale.

Our passion for gaming is at the core of everything we do, inspiring us to collaborate seamlessly. We're not afraid to take on big challenges and push for bold, innovative solutions. Every decision we make is guided by the goal of delivering maximum value and creating a significant, positive impact on our projects. By consistently going above and beyond, we transform every interaction into an exceptional partnership, building trust and delivering excellence.

ABOUT THE ROLE:

We are seeking a Principal Game Engineer to join our growing co-dev team.

In this role, you will take ownership of the systems players feel most directly: gameplay, UI, 3Cs (character, camera, and controls), and AI. Working across a variety of partner projects, you will design, implement, and refine the systems that drive the moment-to-moment experience, bringing expert engineering judgement to everything from input handling and camera behaviour to UI architecture and core gameplay systems. As a principal engineer, you will set the technical direction in your area, act as a trusted, customer-facing point of contact for our partners, and raise the bar for quality across the wider team.

An ideal candidate is passionate about games, has deep experience building player-facing systems in Unreal Engine (or similar), combines expert C++ and C# skills with strong 3D maths, and has a track record of delivering polished, responsive player systems and experiences.

WHAT YOU'LL DO:

• Player Experience Development: Design, implement, and polish gameplay features, UI systems, and 3Cs (character, camera, and controls) that feel responsive, intuitive, and satisfying in players' hands.

• Technical Leadership: Own the technical direction for player experience work across projects, making sound architectural decisions, anticipating risks, and guiding solutions from prototype through to ship quality.

• Customer-Facing Collaboration: Act as a senior technical representative to our partners, gathering requirements, presenting solutions, communicating trade-offs clearly, and building the trust that underpins great co-development relationships.

• Critical Problem Solving: Apply strong analytical and debugging skills, including profiling and diagnostic tools, to investigate and resolve complex technical issues across gameplay, UI, and engine-level systems.

• Mentorship: Support and mentor engineers across the team, sharing expertise in player experience engineering and helping to grow the studio's capabilities in gameplay, UI, and 3Cs.

• Code Review: Champion high standards of code quality, performance, and maintainability through code reviews, constructive feedback, and by setting the example in your own work.

WHAT WE VALUE:

• Expert Software Engineering: Extensive professional experience developing and shipping games, with the depth of judgement expected at a principal level and a history of delivering high-quality, player-facing systems.

• Strong C++ and C# Skills: Expert proficiency in C++ and C#, with a commitment to writing clean, maintainable, and efficient code.

• Strong 3D Maths: A firm grasp of the linear algebra and geometry that underpin cameras, character movement, animation, and gameplay systems.

• Unreal Engine Skills: Deep experience developing player-facing systems in Unreal Engine, including the Gameplay Framework, UMG/Slate, and input and camera systems. Unreal experience is preferred, though we also value strong Unity backgrounds.

• Analytical Mindset: Strong analytical skills and a proactive, methodical approach to identifying, diagnosing, and resolving technical challenges.

• Customer-Facing Communication: Confidence and clarity when working directly with partners and stakeholders, with the ability to explain complex technical topics to varied audiences.

• Player Focus: An instinct for what makes games feel great, and the craft to translate that instinct into responsive controls, readable UI, and satisfying gameplay.

• Team Collaboration: Strong communication skills and the ability to work collaboratively with engineers, designers, artists, producers, and project leads.

• Passion for Gaming: A genuine enthusiasm for games and a desire to help create engaging, high-quality experiences for players.

WHAT YOU MAY ALSO HAVE:

• Console Experience: Experience shipping titles on current-generation consoles such as PlayStation 5, Xbox Series X/S, or Switch 2.

• Unity Experience: Professional experience developing and shipping games in Unity alongside your Unreal background.

• Advanced Unreal Experience: Familiarity with custom engine modifications, plugin development, the Gameplay Ability System, or working from Unreal Engine source.

• Accessibility Knowledge: Experience designing and implementing accessible controls, UI, and player options.

• Co-Development Experience: Prior experience in a co-dev, outsourcing, or external development environment working with multiple partners and codebases.

WHAT WE CAN OFFER:

Competitive Salary and Benefits Package: Your health and wellbeing is important to us, so we offer a variety of benefits including:

• Hybrid Working Arrangement: Our office in Cardiff is located right in City Centre, just a couple minutes away from the Cardiff Central Train Station! As a member of our team, you’ll have the flexibility to work at home and collaborate with your fellow engineers in person.

• Private Pension via Salary Sacrifice

• Optional Private Medical, Dental, and Vision coverage

• Annual Leave, plus Bank Holidays and Winter Break Office Closure

• Annual Research Credit: We always encourage personal growth, so we provide all of our team members with an annual credit to further enhance your skills!

• Professional Development: We offer annual reviews, as well as opportunities to collaborate across disciplines, internal tech talks, and the chance to learn from specialists with backgrounds from across the games and software development industries.

• Work-Life Balance: We really believe that home life comes first and we promote a flexible working environment. And as an added bonus: We don’t crunch!

• Family Friendly: We understand the importance of family, which is why we offer 6 weeks full of Maternity, Paternity, and Adoption Leave to support you during this exciting time!

• Office Perks: In addition to everything above, we also provide:

  • Weekly Team Lunches

  • Snacks, Including the Good (Yorkshire) Tea

  • Fully Equipped Team Lounge, Including our Favourite Consoles and Games

  • And, most importantly, a supportive and creative working environment made up of talented and friendly people, as well as the opportunity to work on some pretty cool games and projects – if we do say so ourselves!

A FRIENDLY NOTE FROM THE RECRUITMENT TEAM:

Let us do the work for you: Even if your profile isn’t an exact match for all of the qualifications listed above, we still want you to apply. Our team members come from a variety of different industries, not all of which are immediately relevant to game or software development, and we welcome all candidates of similarly varied backgrounds, communities, and identities.

Rocket Science is an equal opportunity employer and is committed to providing a worry-free workplace void of discrimination or harassment. Rocket Scientists are expected to foster and champion an environment in which everyone has the opportunity to feel included and is afforded the respect and dignity they deserve.

Rocket Science does not accept unsolicited résumés from recruiters, employment agencies, or staffing firms.