How do you handle updates to the knowledge base in production?

Handle updates through either incremental upserts, where you detect changed documents and re-embed only those, or periodic full rebuilds when the corpus is small enough or changes fundamentally. For large corpora, maintain document hashes or timestamps and re-process only modified items. Use stable document IDs so upserts overwrite cleanly. When embedding models change, rebuild is unavoidable since old and new embeddings are incompatible. Plan a migration strategy that queries both indexes during transition, or run indexing offline and swap atomically.