Partial classes are the compiler’s way of letting you pretend a type lives in more than one file. The pieces are stitched together at build time, so from your code’s perspective it’s one big class.
Use them when you need to mix generated code with handwritten logic (UI
bindings, serializers, DOTS codegen, etc.) or when a monolithic class is
trying to eat your editor. Drop partial on the type in each file and
split responsibilities into folders instead of one 900‑line blob.
Warning: splitting purely to avoid scrolling is just papering over design debt. If you’re manually chopping a class, consider refactoring it into smaller, focused types.
Think of partials as duct tape for classes: helpful when the tool binds you into a corner, hazardous if you grab a roll every time you see a long file.