Postgres’s extensible index AM story doesn’t get enough love, so it’s nice to see someone really lean into it for LIKE. Biscuit is basically saying: “what if we precompute an aggressive amount of bitmap structure (forward/backward char positions, case-insensitive variants, length buckets) so most wildcard patterns become a handful of bitmap ops instead of a heap scan or bitmap heap recheck?” That’s a very different design point from pg_trgm, which optimizes more for fuzzy-ish matching and general text search than for “I run a ton of LIKE '%foo%bar%' on the same columns”.

The interesting question in prod is always the other side of that trade: write amplification and index bloat. The docs are pretty up-front that write performance and concurrency haven’t been deeply characterized yet, and they even have a section on when you should stick with pg_trgm or plain B-trees instead. If they can show that Biscuit stays sane under a steady stream of updates on moderately long text fields, it’ll be a really compelling option for the common “poor man’s search” use case where you don’t want to drag in an external search engine but ILIKE '%foo%' is killing your box.