Senior Principal Gameplay Engineer

• 15+ years' relevant experience in game engineering, including substantial contributions to gameplay, systems design and core technology.
• Proven experience operating as a Principal Engineer, Senior Principal Engineer, Technical Lead or equivalent, guiding complex technical work and influencing engineering decisions.
• Strong programming skills in C++ and C#, with extensive experience designing and debugging maintainable systems.
• Strong practical experience with test-driven development and testable software architecture.
• Experience implementing and troubleshooting multiplayer replication.
• Experience developing or maintaining anti-cheat systems and understanding their relationship with gameplay and network architecture.
• Experience creating Blueprint-based systems and integrating them with native code.
• Practical experience with Unreal Engine 4, Unreal Engine 5, Unity and custom game engines.
• Experience developing engineering tools and contributing to core technology.
• Experience implementing UI functionality and connecting player-facing interfaces to underlying game systems.
• Strong mentoring, collaboration and communication skills, including explaining technical decisions across disciplines.

• Experience supporting shared-world multiplayer games or titles with ongoing content updates.
• Experience validating gameplay on authoritative systems and investigating unexpected network behaviour.
• Experience improving automated test coverage within established game codebases.
• Experience modernising complex systems while maintaining compatibility with live functionality.
• Experience creating designer-facing tools and reusable gameplay frameworks.
• Experience guiding engineering standards or technical improvements across multiple teams.
• Experience working within co-development partnerships and adapting to established architectures and workflows.
• Previous shipped title(s) involving gameplay systems, multiplayer technology, tools or technical leadership.

Based just outside Birmingham, Flix is made up of welcoming, passionate, active gamers that support one another in all aspects of development. We offer you to:

• Join a friendly, nurturing work environment with the opportunity to build games as part of an extremely talented, ambitious studio.
• Work on market-leading AAA titles and IP with globally reputable studio and publisher partners.
• Be part of a sustainably growing game developer studio as we consciously expand our team and projects on a case-by-case basis.
• Learn within an independent studio across a wide range of projects and opportunities both internal and external.

Please note: We welcome applicants who prefer to work from home; however, we cannot offer visa sponsorship for this opportunity at this time.

The Senior Principal Gameplay Engineer provides technical direction and specialist gameplay engineering expertise across internal projects and co-development partnerships. The role combines extensive systems design experience with hands-on development to resolve complex challenges and improve the reliability, maintainability and quality of game technology.

The role will initially support a shared-world multiplayer adventure, contributing to gameplay systems, multiplayer replication, tools and core technology. Responsibilities and project assignments will evolve as existing projects develop and new projects are commissioned.

Working closely with Engineering, Design, UI/UX, QA and Production, you will guide the architecture and implementation of interconnected systems. You will draw on experience in test-driven development, anti-cheat, Blueprint systems and engine technology to support robust gameplay and efficient development workflows.

The role requires strong technical judgement and clear communication, alongside the ability to guide engineering decisions across teams while remaining directly involved in implementation, debugging and mentoring.

• Shape the technical design and architecture of gameplay systems, balancing player experience, maintainability and delivery requirements.
• Own complex engineering work from initial investigation through to implementation, validation and ongoing improvement.
• Design and maintain multiplayer replication systems, investigating synchronisation issues and ensuring consistent gameplay behaviour across connected players.
• Develop and improve anti-cheat functionality, working with relevant specialists to strengthen game integrity and investigate vulnerabilities.
• Apply test-driven development where appropriate and guide effective automated testing and regression prevention.
• Design reusable gameplay and Blueprint systems that support iteration while maintaining clear technical boundaries.
• Develop tools that improve engineering and design workflows, reducing repetitive work and supporting effective diagnostics.
• Contribute to UI functionality and underlying systems, collaborating with UI/UX colleagues to deliver clear and responsive interactions.
• Investigate defects spanning gameplay, networking, tools and core engine technology.
• Guide improvements to established systems, managing dependencies and preserving compatibility with existing functionality.
• Provide technical mentoring and code review, helping engineers assess trade-offs and strengthen implementation quality.
• Communicate architectural decisions, technical risks and delivery dependencies to discipline leads and Production.
• Document significant systems and promote engineering practices that benefit the wider team.

Role ID: FLX-R116