A developer refactored C# networking for BlindSpot, an online FPS game, targeting zero-latency and stutter-free frames. The overhaul minimized Garbage Collection (GC) overhead by replacing a List-based buffer with a fixed-size sliding window using a single 8KB byte array and index offsets, eliminating frequent allocations.

To handle thread safety, they implemented a producer-consumer pattern with a ConcurrentQueue. This decouples the network thread from Unity's main thread, preventing crashes when accessing game objects, and uses a lock-free algorithm to avoid contention. Packet processing was also optimized by replacing a switch-case with a direct O(1) lookup array of delegates.

The final optimization uses ArrayPool to rent and return payload buffers, reducing GC pressure and memory fragmentation. To handle pool-allocated array sizes, they added a size variable to the packet structure. While not completely zero-allocation, this multi-pronged approach significantly improves frame stability for real-time gameplay.