What Flex does
Flex is a payment platform for businesses to accept HSA/FSA, unlocking the $150B per year sitting in HSA/FSA accounts.
1 open role
What the role involves
Flex Flex enables businesses to accept HSA/FSA payments, unlocking the $120B sitting in these accounts. We’re an early stage startup backed by Y-Combinator, SV Angel, Liquid2, and Precursor Ventures, with angels from Stripe, Shippo, Unit21, and OpenAI. We ascribe to Netflix’s “Dream Team” culture and strive for every team member to be exceptional in their role and as teammates. Our team is remote across US time zones with quarterly in person meetups. Given this, the ability to operate autonomously is an absolute must. The role We’re looking for an exceptional engineer who wants to drive the future of HSA/FSA Payments. In this role, you will: Contribute to building the highest converting HSA/FSA checkout experience. Build simple and elegant APIs making it easy and seamless to integrate with Flex. Design and develop novel, scalable solutions for HSA/FSA payment infrastructure. Interact directly with customers to help define the future roadmap. Work with the following technologies: NextJS, Rust, Typescript, Postgres, Redis, AWS. You You might thrive in this role if you: Have 3+ years of relevant engineering experience at tech and product-driven companies. Demonstrate proficiency with Typescript, React, and other web technologies. Are proficient with some backend language (we use Rust). You have first hand experience in deploying to AWS Cloud infrastructure. Thrive in dynamic environments, juggling multiple projects and navigating ambiguity with ease. Previous startup experience ideally, at a seed through series B startup. Attitude: Low Ego - You’re not above any task. You readily accept feedback and view it as an opportunity for growth. Collaborative - You thrive in team settings, naturally working across functions to drive the best outcomes for our customers. Hustler - You put in the effort required to make things happen. Self starter - You know how to teach yourself new technologies, skills etc. Benefits Equity compensation Medical, dental and vision plans Unlimited PTO and sick days Parental leave Flex is an equal opportunity employer and encourages all applicants from every background and life experience. We celebrate diversity and do not discriminate based upon race, religion, color, national origin, sexual orientation, gender identity, gender expression, age, status as a protected veteran, status as an individual with a disability, or other applicable legally protected characteristics.
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Company facts compiled from public sources and last refreshed 9 September 2026. Details change; treat the company’s own site as the authority.