About Flex

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, and Rethink Capital, and 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.

About the Role

We’re looking for a Product Designer to own end-to-end design for our merchant experience and partner closely with our 16-person engineering team to ship intuitive, high-impact product at startup speed. You’ll work hand-in-hand with engineers, our founders, sales, and most importantly our merchants themselves to deeply understand user needs and translate them into thoughtful product decisions.

You’ll start by embedding with the merchant team, owning the experience our brand partners use every day, and grow into a generalist design role across the broader Flex product surface. This is a role for someone who thrives in ambiguity, takes initiative, and is excited about building at an early-stage company.

What You’ll Do

• Own product design end-to-end on the merchant team, from discovery and user research through final UI and shipping with engineers

• Lead user research: run merchant interviews and surveys, hop on sales and customer calls, and turn what you learn into clear product direction

• Partner with engineering and the founding team to define the merchant roadmap, scope features, and ship quickly without sacrificing craft

• Design clear, well-considered user flows in Figma and the visual UI to support them

• Use AI tools (Claude, Cursor, Cowork, v0, etc.) to prototype, validate, and iterate on ideas faster than traditional design workflows allow

• Collaborate with our team on evolving and maintaining the Flex design system

• Pitch in across the company when needed (the occasional marketing asset, website tweak, or one-off) without needing it to be your job description

• Contribute to a culture of learning, problem-solving, and operational excellence

Who You Are

• 3+ years of experience as a product designer, ideally with time at a high-growth startup or fast-moving product team

• A traditional, user-first product designer: you start with understanding the user and the problem, then design the experience. Visual polish comes after

• Strong in the middle ground of product design: comfortable with both user research and visual design, but your real strength is designing the user flow and experience that connects them

• Expert in Figma. It’s your primary tool

• Strong cross-functional collaborator: you’ve worked closely with engineers and business stakeholders day-to-day, not just other designers

• Comfortable being user-facing: you’ll happily jump on a call with one of our biggest merchants to dig into their experience, or sit in on a sales call to understand how prospects think

• Actively use AI in your design workflow today, for prototyping, exploration, or accelerating your work, and stay current as the design industry evolves around it

• Low ego, resourceful, curious, and excited to wear multiple hats at an early-stage company

• Excellent written and verbal communication skills

• Take ownership and follow through on commitments

Nice to Have

• Experience designing B2B / merchant-facing products, payments, or fintech

• Experience building or contributing to a design system

• Comfort using AI tools to ship code or prototypes (e.g., building or maintaining a marketing site in Cursor or similar)

• Background in healthcare, HSA/FSA, or e-commerce checkout

Why Join Flex

• A mission-driven team making healthcare spending effortless

• Early-stage impact: your work will directly shape our growth and success

• Collaborative, high-trust, and transparent culture

• Competitive compensation and equity package

• Flexible, remote-friendly work environment

How to Apply

Please submit your resume and a portfolio link with your application. Portfolios are required for inbound applicants. We want to see how you think about users, problems, and product flows, not just final visuals.

Flex is an equal opportunity employer and encourages applicants from all backgrounds and life experiences. We celebrate diversity and do not discriminate based on race, religion, color, national origin, sexual orientation, gender identity, gender expression, age, veteran status, disability status, or any other legally protected characteristic.