LangChain, a startup that develops a platform for creating artificial intelligence applications, has raised $300 million at a valuation of $3 billion, the Wall Street Journal writes. The company's valuation is more than double what it was in October last year. The fundraising round was led by Alphabet's CapitalG fund. The funds received are planned to be used to expand LangSmith's corporate platform and increase the workforce from 435 to 850 employees by the end of next year.