Full-text search for docs

Design a small full-text search feature for a help-center / docs site with ~500K documents (articles, FAQs), ~50 QPS of search traffic, and a few thousand content edits per day. Requirements: typo tolerance and prefix/autocomplete, relevance ranking (title matches beat body matches, recency a tiebreaker), filter by category/product, results in <100ms p95, and edits should appear in search within a minute. The team is small, minimize operational complexity.