Flex was founded to solve a simple but costly problem: making it easy for health and wellness brands to accept HSA and FSA payments online. We're backed by First Round, Core VC, Rethink Capital power checkout for Equinox, Dermstore, Therabody, and Ultrahuman to name a few. For years, only giants like Amazon and Walmart could process these payments at checkout, leaving smaller merchants - and their customers - to deal with frustrating reimbursement paperwork.

Our technology verifies product eligibility in real time, handles split payments for eligible and non-eligible items, and can even issue Letters of Medical Necessity during checkout. With $150 billion in annual HSA/FSA spending potential, we’re giving brands the tools to unlock new revenue and making it easier for consumers to use the benefits they’ve earned.

We’re looking for a Frontend Engineer to own developing our applications that merchants and consu...