Substrate Labs

Founders Ben and Rob have been friends since meeting at Venmo in 2013. Ben worked at Stripe for 8 years. Rob worked at Fin (human-in-the-loop AI executive assistant, before LLMs) and was founding engineer at Substack. We started our first product, Substrate in 2023, a platform for building agentic workflows, and raised an $8M seed round led by Lightspeed. We were pushing the envelope on both infra (serving multi-model workloads efficiently) and developer experience (ahead of our time in several ways). Though we found solid traction with startups, we realized inference was a red ocean especially upmarket, and decided to spin down the product/team at the end of 2024. We’ve spent the last 6 months prototyping and discarding ideas, and we’re now gearing up to launch our latest vision, a consumer AI application.