http://programmer.ie/tags/migration/ Recent content in Migration on Programmer.ie: Modern AI programming Hugo en-us Mon, 07 Sep 2026 13:10:00 +0000 http://programmer.ie/books/embeddings-from-first-principles/17-chapter/ Mon, 07 Sep 2026 13:10:00 +0000 http://programmer.ie/books/embeddings-from-first-principles/17-chapter/ <p><em>Part V — Embedding Spaces Are Not Universal</em></p> <h2 id="the-upgrade-that-broke-search-quietly">The upgrade that broke search quietly</h2> <p>Production runs embedding model v1. A better v2 ships. Someone updates the client library. New documents get v2 vectors; the 10 million existing vectors are still v1. Nothing errors. Queries are embedded with v2 and compared against a mix of v1 and v2 vectors.</p> <p>Recall drops a few points. Nobody notices for a month, because the system still returns ten results and they still look plausible. The v1 and v2 vectors are in different universes (Chapter 16), and half the index is now in the wrong one.</p>