River AI Raises $1.1B for Model Customization

River AI, a startup specializing in enterprise open-source AI model customization, has raised $1.1 billion across a seed and Series A round. Backers include General Catalyst, AMP PBC, Nvidia, AMD Ventures, Y Combinator, and Temasek. The company is led by Igor Babuschkin, a co-founder of xAI and former DeepMind researcher. River AI's flagship product, the River API, uses a technique called LoRA to customize large language models ranging from 35 billion to 1 trillion parameters in 15 to 20 minutes. The company claims its models can be four times more cost-efficient than proprietary alternatives and plans to expand into agent personalization and custom AI chip development.