by Maria Deutscher

Six months after its last nine-figure funding round, Harvey AI Corp. today announced that it has raised $550 million at $15.5 billion valuation.

Diffusion and Lightspeed Venture Partners led the deal. They were joined by more than a dozen other backers, including Sequoia, Kleiner Perkins and Goldman Sachs.

Harvey sells a cloud platform that law firms use to automate manual work for their attorneys. The company says its installed base includes 80% of the 100 highest-ranked law firms in the U.S. Harvey is also popular among large enterprises’ in-house legal teams: It counts half the Fortune 10 as customers.

The company’s platform enables users to store up to 100,000 documents in a repository called Vault. A built-in search engine uses artificial intelligence to surface useful patterns. For example, an attorney could ask Harvey to find supplier contracts that must be modified to comply with a new regulation.