I'm not sure how most modern game engine work these days but Counter-Strike Global Offensive traces its roots back to Quake which uses BSP, part of which includes compile-time visibility checking and compile-time lighting calculations. Higher reliance on models (over map geometry) and dynamic lighting invalidate these optimisations to some extent, but the base is still there. Source also makes use of LOD models (if the player is far away from a model, a low polygon count model is used instead), and lower versions of DirectX force the use of simplified model geometry (per-DirectX level models are generated at compile time).
There are probably other things too - Valve has published some papers at https://www.valvesoftware.com/en/publications