Senior Software Engineer, Backend

<div class="content-intro"><p>Flex is a growth-stage, NYC headquartered FinTech company that is creating the best rent payment experience. It’s hard to believe that it’s 2026 and paying rent on time is expensive, inflexible, and difficult. We’re here to change that! Flex enables our users to pay rent throughout the month on a schedule that better fits their finances and budget. Our mission is to empower as many renters as possible with flexibility over their most significant recurring expense. After deliberately keeping a stealth profile as we built up unprecedented investor support and an enthusiastic user base, we are looking for motivated individuals to help us keep our mission growing. Will you be a part of the team?</p></div><p><span style="font-family: helvetica, arial, sans-serif; font-size: 12pt;"><strong>About Our Opportunities</strong></span></p> <p><span style="font-family: helvetica, arial, sans-serif; font-size: 10pt;">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 Senior 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 — leading scoping, design, and implementation for the APIs you own, 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.</span></p> <p><span style="font-size: 12pt; font-family: helvetica, arial, sans-serif;"><strong>About Our Team(s)</strong></span></p> <p><span style="font-family: helvetica, arial, sans-serif; font-size: 10pt;">We have some really exciting teams who are looking for an amazing engineer like you! Check them out!&nbsp;</span></p> <ul> <li style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><span style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><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</span></li> <li style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><span style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><strong>Fin Platform - </strong>Fin Platform is the monitoring and operations layer for Flex's billing and payment systems, covering dashboards, SLIs/SLOs, runbooks, deployment and on-call procedures to ensure reliability and readiness.</span></li> <li style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><span style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><strong>Money Team</strong> - builds and owns the platforms, tooling, and documentation powering Flex's payments, wallet, and settlement finance systems.</span></li> </ul> <p><span style="font-size: 12pt; font-family: helvetica, arial, sans-serif;"><strong>Who Thrives Here?&nbsp;</strong></span></p> <ul> <li style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><span style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><strong>A Doer </strong>— you get things done efficiently, and you're comfortable rolling up your sleeves when something's blocking the team.</span></li> <li style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><span style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><strong>An Owner</strong> — you take full accountability for what you build, from design through production, and you always have a plan B.</span></li> <li style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><span style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><strong>Someone Collaborative </strong>— you bring people together to pressure-test ideas rather than working in a silo.</span></li> <li style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><span style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><strong>Someone with Precision</strong> — your code and your communication are both clear, because ideas only matter once others can act on them.</span></li> <li style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><span style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><strong>Someone Resilient </strong>— systems break and priorities shift, and you adapt without losing momentum.</span></li> <li style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><span style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><strong>Someone Humble</strong>— you care more about getting to the right answer than being the one who's right.</span></li> </ul> <p class="font-claude-response-body break-words whitespace-normal"><span style="font-family: helvetica, arial, sans-serif; font-size: 12pt;"><strong>Qualifications</strong></span></p> <p class="font-claude-response-body break-words whitespace-normal"><strong><span style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><em>Minimum Qualifications</em></span></strong></p> <ul> <li style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><span style="font-family: helvetica, arial, sans-serif; font-size: 10pt;">Minimum of 6 years experience in software engineering</span></li> <li style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><span style="font-family: helvetica, arial, sans-serif; font-size: 10pt;">Minimum of 4 years experience with Java</span></li> <li style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><span style="font-family: helvetica, arial, sans-serif; font-size: 10pt;">Ability to work on a globally-distributed team with a high degree of ownership</span></li> <li style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><span style="font-family: helvetica, arial, sans-serif; font-size: 10pt;">Experience working with technical and non-technical stakeholders, successfully aligning and setting expectations on scope and delivery</span></li> <li style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><span style="font-family: helvetica, arial, sans-serif; font-size: 10pt;">Ability to grow in a fast-paced and dynamic environment that will challenge you to always bring your best</span></li> <li style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><span style="font-family: helvetica, arial, sans-serif; font-size: 10pt;">Experience building robust, fault-tolerant systems with multiple external dependencies</span></li> <li style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><span style="font-family: helvetica, arial, sans-serif; font-size: 10pt;">Experience designing, building, and maintaining data pipelines</span></li> <li style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><span style="font-family: helvetica, arial, sans-serif; font-size: 10pt;">Proficient in Java frameworks and tools used at Flex, including Spring (core/web/boot), Gradle, JUnit, and JVM (memory/performance tuning, GC)</span></li> <li style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><span style="font-family: helvetica, arial, sans-serif; font-size: 10pt;">Experience with Service-Oriented Architecture, REST APIs, Message Queues, and scalable architectures</span></li> <li style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><span style="font-family: helvetica, arial, sans-serif; font-size: 10pt;">Experience with AWS (EKS, Aurora RDS, Elasticache, DynamoDB) and containerization tools</span><br><br></li> </ul> <p><strong><span style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><em>Preferred Qualifications</em></span></strong></p> <ul> <li style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><span style="font-family: helvetica, arial, sans-serif; font-size: 10pt;">Proficient in CI/CD systems (preferably GitHub Actions), git, and automation</span></li> <li style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><span style="font-family: helvetica, arial, sans-serif; font-size: 10pt;">Skilled in observability and monitoring tools, such as DataDog, to ensure high availability</span></li> <li style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><span style="font-family: helvetica, arial, sans-serif; font-size: 10pt;">Experienced with big data platforms and tooling, including Snowflake</span></li> <li style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><span style="font-family: helvetica, arial, sans-serif; font-size: 10pt;">Proficient in Infrastructure as Code, using tools like CDK and Terraform</span></li> <li style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><span style="font-family: helvetica, arial, sans-serif; font-size: 10pt;">Skilled at elevating team standards through best practices, and mentoring junior engineers</span></li> <li style="font-family: helvetica, arial, sans-serif; font-size: 10pt;"><span style="font-family: helvetica, arial, sans-serif; font-size: 10pt;">Excellent written and verbal communicator, with experience in cross-functional collaboration</span></li> </ul><div class="content-pay-transparency"><div class="pay-input"><div class="description"><h3><strong>Compensation</strong></h3> <p>Flex takes a market-based approach to pay, and compensation may vary depending on your primary work location. Work locations are categorized into one of three tiers based on a cost of labor index for that geographic area. The successful candidate’s starting pay will be commensurate with their experience, qualifications, and Flex’s internal leveling guidelines and benchmarks.</p></div><div class="title">Tier 1 (NYC/Bay Area, Los Angeles, Seattle)</div><div class="pay-range"><span>$172,000</span><span class="divider">&mdash;</span><span>$215,000 USD</span></div></div><div class="pay-input"><div class="title">Tier 2 (Austin, Washington D.C. Philadelphia, San Diego, Chicago, Atlanta)</div><div class="pay-range"><span>$154,800</span><span class="divider">&mdash;</span><span>$193,500 USD</span></div></div><div class="pay-input"><div class="title">Tier 3 (Salt Lake City, all other USA cities)</div><div class="pay-range"><span>$146,200</span><span class="divider">&mdash;</span><span>$182,750 USD</span></div></div></div><div class="content-conclusion"><h3><strong>Life at Flex</strong></h3> <p>We understand that it takes a diverse team of highly intelligent, curious, determined, empathetic, and self aware people to grow a successful company. Our HQ is located in New York City, but we have employees located throughout the US, Australia, Canada and South America. We are growing quickly, but deliberately, with a focus on building an inclusive culture. Our dynamic team has incredible perspectives to share, just as we know you do, and we take great pride in being an equal opportunity workplace.</p> <p><strong>Offices</strong></p> <p>Roles posted in New York, San Francisco, and Salt Lake City are hybrid positions with on-site expectations of 2-3 days per week in our local offices. For candidates outside of these areas, you may be eligible for our relocation assistance program.</p> <p><strong>Benefits</strong></p> <p>For full-time U.S. employees we offer:</p> <ul> <li>Competitive medical, dental, and vision</li> <li>Company equity</li> <li>401(k) plan with company match&nbsp;</li> <li>Unlimited paid time off + 13 company paid holidays</li> <li>Parental leave&nbsp;</li> <li>Free Flex subscription</li> </ul> <p>&nbsp;For full-time non-U.S. employees, we offer:</p> <ul> <li>Competitive compensation + company equity</li> <li>Unlimited PTO</li> </ul></div>