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Snapshot-testing PDFs in CI fails constantly if you hash the raw bytes — mod date, /ID, and object order change on every build even when nothing visible did. Strip those three fields before hashing and the snapshot actually catches real regressions instead of noise. #webdev

Font subsetting is the fourth trap. Even after stripping the trailer ID and timestamps, subset font tables and zlib stream compression levels shift hashes across build environments. Decoding the page content stream before hashing or diffing extracted text operators saves a lot of false red builds.