Senior Core Engine Engineer

The opportunity The team that brought Unity to visionOS and enabled real-time interaction via Play-to-Device is growing in preparation for something even more ambitious: adapting PolySpatial to stream Unity content into other game engines and 3D environments—in-process, cross-process, and over the network. We're looking for engineers eager to help us invent how different real-time 3D runtimes communicate and render under real-world constraints. You’ll work at the intersection of core engine tech, high-performance networking, distributed systems, and graphics. This is your opportunity to build the fundamental infrastructure for the next generation of interconnected game and 3D ecosystems. You’ll own critical tech that enables Unity to run as a guest within other processes, engines, and distributed systems. This is deep engine work requiring a holistic understanding of execution models, serialization, asset lifecycles, and runtime performance—all operating reliably in host environments we don’t control. You'll design systems that allow Unity to load, run, and synchronize assets when we don't own the main loop, design clean, extensible architecture, then drop into assembly to shave off milliseconds. What you'll be doing Own and evolve critical subsystems across the engine stack, from low-level C++ to high-level C# APIs across editor, build, and runtime code. Design and implement high-performance, extensible APIs intended for embedded, cross-process, and networked configurations. Develop schemes to manage execution timing and resource contention within or between processes and over the network with minimal overhead Orchestrate loading, change tracking, serializing, and synchronizing components and assets in bandwidth and latency-constrained environments. What we're looking for Core Engine Expertise: Experience building or fundamentally extending game engine cores, middleware, or foundational systems (e.g., serialization, build pipelines, memory subsystems). Architectural Vision + Practical Implementation: Design modular, testable systems, then implement and debug them yourself end-to-end High-Performance Coding: Strong C++ and C# skills, with practical understanding of CPU caches, branch behavior, memory layout, and profiling. Engine-Wide Breadth: Hands-on experience across multiple engine domains (e.g., physics, animation, input, assets) and how they interact. You might also have Experience with WASM, embedded runtimes, or compiler pipelines (Mono, CoreCLR, etc.). Deep knowledge of multithreading, job systems, lock-free techniques, and/or Unity DOTS. Experience solving cross-platform issues across consoles, mobile, and desktop. Familiarity with networking concepts such as replication, authority, and RPCs. Additional information Relocation support is not available for this position Work visa/immigration sponsorship is not available for this position Benefits At Unity, we want our team members to thrive. We offer a wide range of benefits designed to support well-being and work-life balance. Please note: Benefits eligibility, specific offerings, and coverage vary based on the country and employment status. While specific benefits vary, here are some of the ways we strive to take care of our eligible team members globally: Comprehensive health, life, and disability insurance | Commute subsidy | Employee stock ownership | Competitive retirement/pension plans | Generous vacation and personal days | Support for new parents through leave and family-care programs | Office food snacks | Mental Health and Wellbeing programs and support | Employee Resource Groups | Global Employee Assistance Program | Training and development programs | Volunteering and donation matching program Life at Unity Unity [NYSE: U] is the leading platform to create and grow games and interactive experiences. Creators, ranging from game developers to artists, architects, automotive designers, infrastructure experts, filmmakers, and more, u ... (truncated, view full listing at source)