Snorkel AI raised $350 million at a $3.5 billion valuation, co-led by Insight Partners and S32, with Greylock and Wells Fargo joining. Annualised revenue crossed $350 million, up about seventeen times in a year from roughly $20 million. The reason is a change of business. In September 2025 it stopped selling labelling software and started selling the labelling itself, as a service. That is where the money in training data went: not tools that help a customer label their own data, but expert data made to order for the frontier labs.