Flex
Fintech • SaaS • B2B
Flex is a SaaS payments infrastructure company that enables merchants and brands to accept HSA/FSA and other health-benefit payments. Its API-first platform integrates with e-commerce platforms (Shopify, WooCommerce, etc. ) and supports complex flows like split-card payments, subscriptions, eligibility verification, automated Letters of Medical Necessity, and enterprise-scale reporting to boost conversion and average order value. Flex is aimed at health, wellness and fitness brands that want to unlock pre-tax benefit spend at checkout while staying compliant.
11 - 50 employees
Founded 2023
💳 Fintech
☁️ SaaS
🤝 B2B
Software Engineer
October 23
🇺🇸 United States – Remote
💵 $160k - $220k / year
⏰ Full Time
🟡 Mid-level
🟠 Senior
🧑💻 Full-stack Engineer
🦅 H1B Visa Sponsor
Flex
Fintech • SaaS • B2B
Flex is a SaaS payments infrastructure company that enables merchants and brands to accept HSA/FSA and other health-benefit payments. Its API-first platform integrates with e-commerce platforms (Shopify, WooCommerce, etc. ) and supports complex flows like split-card payments, subscriptions, eligibility verification, automated Letters of Medical Necessity, and enterprise-scale reporting to boost conversion and average order value. Flex is aimed at health, wellness and fitness brands that want to unlock pre-tax benefit spend at checkout while staying compliant.
11 - 50 employees
Founded 2023
💳 Fintech
☁️ SaaS
🤝 B2B
📋 Description
• Contribute to building the highest-converting HSA/FSA checkout experience. • Build simple, elegant APIs that make Flex easy to integrate. • Design and develop scalable solutions for HSA/FSA payment infrastructure. • Interact directly with customers to help define the roadmap. • Work with technologies including Next.js, Rust, TypeScript, Postgres, Redis, and AWS.
🎯 Requirements
• 3+ years of engineering experience at tech and product-driven companies • Proficient in TypeScript, React, and modern web technologies • Skilled in at least one backend language (we use Rust) • Hands-on experience deploying to AWS infrastructure • Comfortable in dynamic, fast-paced startup environments • Prior startup experience (seed–Series B) strongly preferred
🏖️ Benefits
• Equity compensation with competitive salary • Medical, dental, and vision plans • Unlimited PTO and sick days • Paid parental leave • Flexible, remote-first team with quarterly in-person meetups
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