[aleden]

I'm surprised no one has mentioned qpdf.

https://qpdf.readthedocs.io/en/stable/overview.html

It turns a PDF (typically everything in it is compressed binary blobs) into a mixed binary/ASCII file (which itself is a PDF) that can be edited with vim.

[chrnola]

The linked article literally mentions qpdf within the first few paragraphs.

[gpvos]

I'm not sure what you were reading, but the fine article is centred around using qpdf.

[rhaway84773]

It’s mentioned in the gist

> To view the compressed data, you can use a command line tool called qpdf.