Blog

Engineering · August 3, 2026 · 3 min read

Tracked changes that survive translation

An LSP brought us a workflow that every translation tool on the market answers the same way: badly.

The client edits the English document with Word tracked changes. We already translated version 1 into Spanish. They want version 2 in Spanish with the equivalent tracked changes applied — not a fresh re-translation.

The standard answer is to re-translate v2 from scratch and hand the reviewer a clean document. The audit trail — who changed what, and where — is gone. For legal, regulatory, and healthcare content, the audit trail is the point. The redlines are what the reviewer signs off on.

What we built

A delta-aware DOCX pipeline that ingests three things: the original English, the English redlines, and the existing Spanish v1. It computes the delta, translates only what changed, and emits a Spanish v2 with the equivalent insertions and deletions as Word tracked changes — in Spanish, in the right places.

  • The reviewer sees exactly what changed between v1 and v2, as tracked changes, in their language.
  • Unchanged text is untouched — the approved v1 translation survives verbatim.
  • Rounds that took days of manual reconciliation take hours.

Why this matters beyond DOCX

This pipeline exists because a client's real workflow didn't fit any tool, and our answer to that is engineering, not a workaround PDF. It's the same reason we have dedicated pipelines per CAT format, a dual-backend OCR chain, and transcript delivery in your client's own branded template. When standard isn't enough, we build the pipeline — that's not a sales line, it's the product roadmap's actual generating function.

If you have a workflow that makes your current vendor say “that's not supported”, we'd genuinely like to hear it.