Senior Core Engine Engineer

Unity Technologies•San Francisco, CA

About The Position

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 implement the systems that let Unity run reliably inside other processes, engines, and environments. You'll own specific engine features–input, physics, animation, audio, etc.–and make them work across boundaries (engine to engine, editor vs runtime, C++ vs C#) while optimizing for modularity, efficiency, and embeddability. If you like diving into unfamiliar subsystems, solving interoperability puzzles, and squeezing performance out of critical paths, you’ll have plenty of opportunities here.

Requirements

Game Engine Experience: You've developed or heavily modified game engine cores, middleware, or foundation systems
High-Performance Coding: Solid C++ and C# skills, with a working knowledge of cache-friendly data layout, memory management, and real-time optimization.
Versatility: Willing to jump into unfamiliar areas—today a physics integration issue, tomorrow a serialization bug
System Depth: Technical experience in at least one engine area (physics, animation, input, assets, etc.) and how it interacts with the rest of the engine

Nice To Haves

Experience with WASM, embedded runtimes, or compiler pipelines (Mono, CoreCLR, etc.).
Understanding of multithreading, job systems, lock-free data structures, and/or Unity DOTS.
Experience solving cross-platform issues across consoles, mobile, and desktop.
Familiarity with networking concepts such as replication, authority, and RPCs.

Responsibilities

Implement and extend key subsystems across the game engine stack, from low-level C++ engine integrations to high-level C# APIs across editor, build, and runtime code.
Profile and optimize execution timing and resource contention within or between processes with minimal overhead
Improve loading, change tracking, serializing, and synchronizing components and assets in bandwidth and latency-constrained environments.
Refactor engine code into decoupled modules suitable for embedding and shared execution