UI/UX Designer

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. Atomic Theory is a multinational team of seasoned AAA veterans with roots at studios like Blizzard, PUBG, Epic Games, and Unity. We’re passionate about building player-first experiences with strong engineering foundations, performance excellence, and accessibility baked in from day one. With offices in Albany, NY; Austin, TX; Cardiff, UK; and Brighton, UK, we operate globally with one mindset: Get Sh!t Done. ABOUT THE ROLE: As an Mid-Level UI/UX Designer, you are a fully capable, independent contributor who handles complex UI tasks and systems within your domain. You take ownership of mid-scope UI features and solve complex design or technical challenges. You are expected to work autonomously, unblock peers when necessary, and ensure your work is high-quality, stable, and integrated into the project pipeline. At this level, you are not leading the team, but you are a key contributor whose technical and design expertise keeps features moving forward efficiently. WHAT YOU'LL DO:• Design, implement, and optimise complex UI features and systems (menus, HUD modules, dynamic flows, procedural elements). • Develop and maintain UI libraries, reusable components, and critical systems to support your feature domain. • Implement and optimise or have knowledge of custom UI shaders, materials, or advanced animations to achieve specific visual or functional goals. • Debug and solve technical UI issues (engine, blueprint, middleware) to unblock your feature work. • Validate UI functionality and appearance across resolutions, aspect ratios, and gameplay contexts. • Improve personal and small-team workflows to increase efficiency and reliability. • Contribute to UX flows, usability, and interface consistency within your domain. • Maintain documentation for tools, systems, and components to ensure clarity and reproducibili