Figma's API returns 400 for .make files, so I dug into the binary. Turns out it's a ZIP with a custom format: Deflate for the schema chunk, Zstandard for the data, then Kiwi binary decoding. Scripts on GitHub if useful: https://github.com/albertsikkema/figma-make-extractor

I once reverse engineered the Figma .fig file they have utilised quite good compression and data storage techniques for a tech company that uses AWS