What was the problem?
Clinicians would not trust an answer they could not verify. A previous vector-only pilot returned plausible summaries with no traceable source and was shelved.
How did Tekvo build it?
- 01
Rebuilt retrieval as hybrid: BM25 for exact clinical terminology, dense vectors for paraphrase, reciprocal-rank fusion on top.
- 02
Chunked on document structure rather than token count, so a citation resolves to a paragraph a clinician can read.
- 03
Scored citation accuracy as a first-class eval metric, gated in CI alongside answer quality.
What changed?
94% citation accuracy against a clinician-labelled golden set, 1.1s P95 across 2.1M documents, and a review workflow that finally passed clinical governance.