Baseten has raised $1.5 billion in a Series F funding round as the market for AI inference infrastructure continues to expand, the company said Monday. The round was led by Altimeter Capital, Conviction and Spark Capital, with Sands Capital and Wellington Management acting as co-leads.

The San Francisco company said the financing was completed in two tranches, with valuations of $13 billion and $11 billion. The structure reflects rising investor interest in infrastructure that helps companies run AI models in production, especially as customers increasingly combine frontier models with customized systems trained on their own data.

Baseten is positioning itself around what it sees as a shift in how AI applications are built. Rather than relying on a single model, the company says many customers are using a mix of general-purpose foundation models and post-trained models tailored to specific tasks. The company said that approach is becoming more important as open and closed models narrow in performance, cost and customization.

The startup reported that its revenue has grown about 20 times year over year. It also said its platform now handles more than 1 billion inference calls each day across 87 clusters in 18 clouds. That scale underscores the company’s pitch that inference is becoming a core enterprise workload, not just a back-end technical function.

Baseten’s software is designed to manage the infrastructure behind AI applications, including GPU orchestration, autoscaling, observability, billing and developer tools. The company says this allows customers to focus on their models and product experience instead of building the underlying systems themselves.

Chief executive and co-founder Tuhin Srivastava said the industry is moving toward millions of specialized models, and argued that companies will need infrastructure that supports post-training and ownership of model intelligence. In a statement, he said the firms moving fastest are building systems that become more valuable over time as they learn from proprietary data.

Altimeter partner Apoorv Agrawal said the firm believes Baseten’s bet on specialized models has begun to pay off, pointing to strong customer trust and rapid growth in the inference market. He said some of the most sophisticated AI companies are standardizing on the company’s platform.

Baseten said the new capital will be used to hire more staff, expand compute resources and accelerate enterprise sales. The company plans to triple headcount this year, with investment going into engineering, research, operations and go-to-market teams.

Founded in 2019, Baseten has now raised more than $2 billion in total funding, according to the company. Its customers include Abridge, Clay, Cursor, Lovable, Mercor and OpenEvidence, among others.

The latest round adds to a growing wave of funding for infrastructure businesses that support AI application deployment and model serving. As companies move from experimentation to production, demand for tools that can efficiently run custom models at scale is becoming a central part of the AI ecosystem.