During my time as lead engineer at Vodeo Games I helped prototype and develop an unreleased management simulation
game involving multiple gameplay layers and a very large number of complex AI-driven agents, using the Unity engine and C#.
In order to make this game possible, I designed and developed a custom-built "Entity Component System" (ECS) framework serving as a foundation for the simulation. Today, this work has been released as a general-purpose framework for game development with the Unity game engine under the GNU Lesser General Public License, and can be found here: [GITHUB] .
The framework is also fully documented here: [WIKI].
ECS architecture is specialized for high-performance real-time processing of large quantities of dynamic entities. It takes a modular, data-driven approach by defining all "Entities" as sets of simple and modular data-only "Components", which are then processed by various "Systems", each System having a specific and encapsulated function.
As of this writing Unity is developing its own official ECS framework as part of the "DOTS" project, which is likely to continue undergoing significant changes in the near future. The Vodeo ECS, however, is a separate project which was created as a custom-built and more stable alternative to the Unity ECS, while still taking advantage of Burst compilation and the Jobs system.