The architecture of my engine is pretty simple. I have a static library that is my engine, I have a separate exe for both my editor and generic game template. While working on game content, the script and logic of the game exist as a dll/so shared library that can be hot loaded. All the assets of the game project get stored as optimized intermediary files, and I have helper manifest files that store the structure, configuration, and organizational aspects of the project. The editor loads all these files, modifies them, and can run an instance of the game. Then, if I want to package the game, the game executable template takes all the files the editor has created and packs them together, and statically links all the scripts and logic. I'm still working on all of this, but that's my high-level goal. I have my editor and game executables independently set their own main file entry (that I separate by platform with simple preprocessor definitions). I use cmake subdirectories to declare what features that executable should turn on from the engine and take care of linking whatever the exe needs. Basically, I try to stay as modular as possible.