TL;DR: Scaling a production mobile title to 300K+ players across heterogeneous Android and iOS devices requires absolute mastery of runtime memory management. Uncontrolled Garbage Collection (GC) sweeps cause perceptible frame hitches, while unmanaged asset references trigger fatal Out-Of-Memory (OOM) crashes. This deep-dive outlines the production architecture—leveraging Unity Addressables, ScriptableObject event channels, zero-allocation pooling, and ASTC texture pipelines—that reduced our memory footprint by 35%, eliminated GC frame drops, and locked a steady 60 FPS.
1. The Mobile Memory Bottleneck: Why Games Crash on 3GB RAM
On mobile platforms, the OS aggressively terminates apps exceeding memory thresholds. In Unity mobile development, the two primary causes of failure are:
Mono Managed Heap Fragmentation: In Unity's non-compacting Boehm GC, the managed heap only expands—it never shrinks back to the operating system during gameplay. A single spike in allocations permanently balloons the heap footprint.
Monolithic Asset Retention: Direct SerializeField inspector links force all referenced prefabs, 4K textures, and audio clips into RAM upon initial scene loading.
