Staff Software Engineer, Backend

<div class="content-intro"><p>Flex is a growth-stage, NYC headquartered FinTech company that is building the payment layer for life's essential bills, giving households one place to see, split, and pay their bills around how they live and get paid. By offering greater choice over how and when payments are made and allowing eligible on time payments to help build a positive credit history, Flex puts households back in control of their cash flow.</p> <p>That work brings together people with different perspectives who challenge the status quo and take ownership of solving difficult problems. For you, that means doing the best work of your career next to people who make you better, and together bringing ideas to life that make a real impact for the people we serve.</p></div><p><strong>About Our Opportunities</strong></p> <p>Flex exists to make paying rent work the way real life actually works — smoothing out cash flow, helping renters avoid late fees, and letting them build credit instead of falling behind. As a Staff Backend Engineer, you'll design, build, and scale the services and integrations behind Payment, Billing, Identity, and partner integrations that keep rent moving on time for renters every month — setting the long-term technical vision and architecture for the systems you own, leading scoping, design, and implementation across teams, driving your own production rollouts to completion with minimal oversight, and working closely with product, design, and engineering peers to solve renters' most pressing problems in small, frequent iterations rather than big, risky releases. You'll also raise the bar for the engineers around you, mentoring peers and driving consistency and best practices across the org.</p> <p><strong>About Our Team(s)</strong></p> <p>We have some really exciting teams who are looking for an amazing engineer like you! Check them out!</p> <ul> <li><strong>Partner Integrations</strong> - Partner integrations work to standardize APIs, tools, and processes that let external partners connect to Flex for data sharing and payments across entry points like Flex Anywhere and Quick-Pay</li> <li><strong>Money Team </strong>- builds and owns the platforms, tooling, and documentation powering Flex's payments, wallet, and settlement finance systems.</li> </ul> <p><strong>Who thrives here?</strong></p> <ul> <li><strong>A Doer</strong> — you get things done efficiently, and you're comfortable rolling up your sleeves when something's blocking the team.</li> <li><strong>An Owner</strong> — you take full accountability for what you build, from design through production, and you always have a plan B.</li> <li><strong>Someone Collaborative</strong>