Blacksmith raises $66M Series C at $1B valuation

The company reports significant growth, with its customer base expanding from about 5,000 to over 10,000 companies since August. Customers include Granola, Handshake, Supabase, and LangChain. Weekly validation checks have surged from 5 million at the start of the year to 90 million, while annual recurring revenue has grown 17x to reach the tens of millions. CEO Aditya Jayaprakash stated that the largest customers spend over $1 million annually.

Unlike competitors who rent cloud resources, Blacksmith purchases and maintains its own tens of thousands of servers to control performance. Jayaprakash noted that AI coding tools have shifted the bottleneck from writing code to validating it, driving demand. However, the company faces risks from compute shortages and potential competition from AI vendors like Anthropic and OpenAI, whose tools increasingly handle testing internally.