A look inside Unreal Engine’s reflection system: what UHT generates from your headers, how FProperty, FField and UStruct describe types in memory, how Link() builds the layout, and how exec thunks, replication and Blueprint VM bytecode all rely on it. Includes real generated code and practical examples with TFieldIterator, ExportText and ProcessEvent.
https://dev.epicgames.com/community/learning/tutorials/37DEe/reflection-in-unreal-engine-or-how-the-engine-knows-everything-about-your-code