Why Arabic text comes out backwards when you extract it from a PDF (and how to fix it)

If you've ever built a feature that extracts text from PDFs, an Arabic-speaking user has probably filed this bug: "the words come out in reverse order." Not the letters — the words. Every line reads last-word-first.

I spent the better part of a year fixing this class of bugs while building (shaping + bundled fonts) and Arabic PDF → Word (logical-order extraction). No signup needed, so they're easy to use as a reference for what correct output should look like when testing your own pipeline.

If you're dealing with the same class of bugs in Hebrew or Farsi — same four failure modes, same fixes. Questions welcome in the comments; I've probably hit whatever edge case you're stuck on. 🐪