There's a version of this story where we made a mistake and fixed it. That's true but incomplete. The fuller version is about what a structured evaluation process gets right, what it misses, and how the ground can shift under you even when you've done the work.
This is a post-mortem on five weeks of infrastructure work that ended with git rm and 1,452 lines deleted from the lockfile alone.
The library in question is Docling. It's a capable open-source document parser from IBM Research — handles PDFs, tables, figures, DOCX, the lot. On paper it looked like exactly what we needed. In practice it turned out to be a small ML platform hiding inside a Python package, and we didn't fully appreciate that distinction until we were already three acts deep.