AI search engine developer Exa has completed a $250 million Series C funding round led by a16z, boosting its valuation from $700 million last September to $2.2 billion. The funds will enhance Exa's proprietary index, train advanced retrieval models, and scale its infrastructure to manage extensive concurrent requests. Exa's unique full-stack development includes an independent crawler and a third-generation vector database, distinguishing it from traditional search engines. The company now processes one billion monthly queries and collaborates with major AI firms like Cursor and Cognition. Notably, Exa has partnered with Google Cloud Vertex AI to support enterprise customers.