EliseAI has raised $350 million at a $4 billion valuation, doubling its worth in just over a year on the strength of AI agents that automate back-office work for landlords and health systems.

The round was co-led by existing investors Andreessen Horowitz and Bessemer Venture Partners, with new investor Ontario Teachers’ Pension Plan joining alongside Sapphire Ventures and Navitas Capital. CEO and co-founder Minna Song told Fortune the round was entirely primary capital, with no secondary sale for early investors or employees.

Founded in 2017, the New York company builds software that automates administrative and operational tasks across housing and healthcare — two of the largest expenses for American households. Its platform is now used by roughly one in six apartment properties nationwide, and the company crossed $200 million in annual recurring revenue earlier this summer.

This month EliseAI launched Apollo, an AI “teammate” embedded in its platform to assist across leasing, maintenance and renewals. On the healthcare side, its workflows automate patient paperwork from inbound calls and referrals to scheduling, insurance verification and follow-ups.