Flex is a South Korea-based startup offering an AI-powered, all-in-one SaaS platform for HR and finance operations.
<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><h3><strong>About the Role</strong></h3> <p>We are seeking a Director of Product to lead the Martech and Growth platform at Flex - a 0→1 build role at the intersection of data engineering, marketing intelligence, and consumer growth.</p> <p>You will be the first to own this function at Flex, sitting in Product and serving marketing leadership as your primary internal customer. You will build and own the infrastructure, data, and tooling that makes campaigns possible, measurable, and increasingly intelligent.</p> <p>As we scale direct-to-consumer acquisition through paid social and expand into new biller verticals, you will build the data and intelligence infrastructure that makes that growth compounding rather than linear- a unified identity spine, attribution architecture that moves beyond last-click, lifecycle infrastructure that personalizes at scale, and an ML intelligence layer that gets smarter over time.</p> <p>You will be accountable for CAC efficiency outcomes, identity match rate and audience quality on paid platforms, and measurable lift from ML-driven lifecycle interventions - all built from greenfield. This is a role for someone energized by the scope of what isn't there yet.</p> <p>This is a hybrid position with on-site expectations in our New York Headquarters or San Francisco/Bay Area Office, 2-3 days per week. For candidates outside of a required location, you may be eligible for our relocation assistance program.</p> <h3><strong>Responsibilities</strong></h3> <ul> <li><strong>0→1 Martech Architecture:</strong> Design and build Flex's martech stack from the ground up - CDP, identity spine, attribution infrastructure, lifecycle orchestration, and paid media data pipelines. Make deliberate build vs. buy decisions with limited resources and a clear sequencing logic.<br><br></li> <li><strong>Attribution and Measurement Infrastructure:</strong> Build the measurement architecture that tells us what's actually working in paid acquisition — incrementality testing, MMM, modeled conversions. Move Flex from last-click to something defensible.<br><br></li> <li><strong>Identity and Data Architecture:</strong> Design the identity spine that stitches anonymous ad exposure to app install to authenticated user to payment behavior. Own match rate outcomes. <br><br></li> <li><strong>AI/ML Intelligence Layer:</strong> Layer ML-driven capabilities on top of the bought stack - propensity scoring, predictive LTV, dynamic audience segmentation - that create compounding marketing leverage over time.<br><br></li> <li><strong>Paid Media Data Infrastructure:</strong> Own the data layer underneath paid social — server-side conversion APIs, MMP integration, audience sync across Meta and TikTok and be directly accountable for CAC efficiency.<br><br></li> <li><strong>Lifecycle and Campaign Orchestration:</strong> Build the lifecycle infrastructure that powers onboarding sequences, payment reminders, re-engagement programs, and cross-vertical messaging as Flex expands beyond rent into other biller verticals.<br><br></li> <li><strong>Platform Leadership and Stakeholder Engagement:</strong> Act as the primary technical thought partner to the CMO - translating infrastructure capabilities into growth strategy, and translating marketing needs into technical requirements for engineering and data science.<br><br></li> <li><strong>Data Governance and Compliance:</strong> Design consent management, data governance, and regulatory compliance into infrastructure design.<br><br></li> </ul> <h3><strong>Qualifications</strong></h3> <ul> <li><strong>7+ years</strong> of product management experience specifically in martech, growth infrastructure, or data products -directly building and owning the stack, not in adjacencies<br><br></li> <li><strong>0→1 build experience</strong> in a high-growth environment - you've built a martech function, a data platform, or a measurement infrastructure from scratch with limited resources and high ambiguity; you know what it feels like when the playbook doesn't exist<br><br></li> <li><strong>Attribution architecture depth</strong> - you've built measurement systems that work when signals are degraded; you have hands-on experience with incrementality testing, MMM, or modeled conversions<br><br></li> <li><strong>ML shipped in production</strong> - propensity models, predictive LTV, dynamic segmentation, or recommendation systems you can describe technically<br><br></li> <li><strong>CDP ownership</strong> - you've run the vendor evaluation, made the build vs. buy call, managed the integration, and been accountable for match rate and activation outcomes<br><br></li> <li><strong>Paid media data fluency</strong> - direct accountability for CAC going up or down; hands-on experience with server-side conversion APIs, MMP integration, or paid social audience infrastructure<br><br></li> <li><strong>Consumer product context</strong> - your customers are individuals, not enterprise buyers; bonus if that context is fintech<br><br></li> <li><strong>Technical credibility with engineers and data scientists</strong> — you can design systems at the data layer, not just describe product requirements<br><br></li> </ul> <h3><br><br></h3><div class="content-pay-transparency"><div c