Flex enables businesses to accept HSA/FSA payments, unlocking $120B in HSA/FSA balances. The company states its mission is to make health more accessible and is backed by Y-Combinator, SV Angel, Liquid2, and Precursor Ventures, with angel investors from Stripe, Shippo, Unit21, and OpenAI, while operating remotely across US time zones with quarterly in-person meetups. It positions itself as the manufacturing partner of choice that helps a diverse customer base design and build products that improve the world.