According to VGInsights, about 10% of games released on Steam in 2024 used a custom engine, but those games represent 41% of units sold. Most "how an engine works" talks come from the AAA end of that distribution. This one comes from the other end of that distribution: a teaching-scale engine, where every system has to be small enough to understand from first principles. The problems are the same as in a big engine, but the smaller surface is what makes the architecture legible.
In this talk, we'll walk the spine of the engine in modern C++: allocators and handles in the core, the job system, the graphics abstraction question, the asset pipeline split between pipeline-time and runtime, and scene representation including ECS. We finish on serialization, where C++26 reflection (P2996) offers a path past today's reliance on macros and external code generators.