Senior Backend Engineer - Subscriptions

500M+ downloads. 80M+ monthly users. A decade of building – and we’re still accelerating. Flo is the world’s #1 health & fitness app worldwide on a mission to build a better future for female health. Backed by a $200M investment led by General Atlantic, we became the first product of our kind to reach a $1B valuation in 2024 – and we’re not slowing down. With 7M paid subscribers and the highest-rated experience in the App Store’s health category, we’ve spent 10 years earning trust at scale. Now, we’re building the next generation of digital health – AI-powered, privacy-first, clinically backed – to help our users know their body better. The job We're looking for a Senior Product Manager (Payments) to own the strategy and execution of Flo's payments and subscription platform across Web, iOS, and Android. This is a high-impact, high-visibility role at the intersection of monetisation, platform, and operations, working closely with the VP of Product (Revenue) to shape the payment foundation that will support Flo's next stage of global growth. You will work across Product, Engineering, Data, Finance, Legal/Compliance, Support, and commercial stakeholders to build payment experiences and platform capabilities that are reliable, scalable, compliant, and growth-oriented. Payments are a core part of Flo’s growth engine and a critical platform capability for the business. As we continue to scale globally, we need strong product leadership in this area to ensure our payment stack, subscription systems, and monetisation mechanics are robust, efficient, and ready for the next stage of growth. As Senior Product Manager, Payments Platform, you will play a central role in shaping that foundation. Your Experience Must have: * Significant product management experience, with strong exposure to payments, billing, subscriptions, or financial platform products * Deep understanding of online payment systems and subscription mechanics, ideally in a B2C subscription or consumer app environment * Experience with mobile subscription ecosystems, including Apple and Google billing environments * Experience with web payment providers and billing platforms such as Stripe, Adyen, Braintree, RevenueCat, or similar * Experience managing fraud and dispute processes, including chargeback mitigation and refund strategy * Strong grasp of key payments concepts such as: * Payment flows * SCA / 3DS * Tokenisation * Issuer declines * Retries and dunning * Refunds and disputes * Reconciliation * Subscription lifecycle and entitlement logic * Working knowledge of indirect tax compliance (VAT/GST) and how it intersects with subscription billing and multi-market operations * Experience working closely with engineers on platform or infrastructure-heavy product areas * Proven track record of delivering complex cross-functional initiatives in fast-paced environments * Strong analytical skills and ability to use data to diagnose performance issues, evaluate trade-offs, and drive decisions * Excellent stakeholder management, with the ability to work effectively across Product, Engineering, Data, Finance, Legal/Compliance, and Support * Ability to balance strategic thinking with hands-on execution and operational detail Nice to have: * Experience building in-house billing capabilities or implementing payment orchestration layers * Familiarity with tax determination platforms such as Avalara, TaxJar, or Vertex * Experience defining payment flows for external partner programmes (e.g. sponsored access, partner perks, third-party app stores) * Exposure to payment automation and AI applications in payments contexts (e.g. intelligent retry logic, decline prediction, dispute automation What you'll be doing You'll be responsible for: * Own the product roadmap for Flo’s payments and billing platform across Web, iOS, and Android * Define and improve the end-to-end subscription and billing journey, including: * Purchase and checkout flows * Entitlement and receipt validation * Renewals, retries, grace periods, cancellations, and refunds * Payment failure recovery and dunning * Partner with Engineering and Data to improve the performance and resilience of our payment stack, including: * Acceptance rate optimisation * Issuer decline analysis * SCA / 3DS flows * Tokenisation and retry logic * Payment method coverage and routing * Build the product capabilities, internal tooling, and automations required to support scalable and audit-friendly payment operations * Work closely with Finance and Operations teams to improve reconciliation, reporting accuracy, and process efficiency * Own the tax compliance product surface, working with Finance and Legal to ensure correct tax determination, indirect tax handling (VAT/GST), and compliance with marketplace facilitator obligations across our key markets * Identify and drive monetisation opportunities linked to the payments experience, such as checkout optimisation, refunds strategy, pricing mechanics, promos, and payment method expansion * Lead fraud and dispute management strategy, including chargeback reduction, fraud detection tooling, and refund policy optimisation * Establish clear frameworks for experimentation and decision-making, including A/B testing, KPI definitions, and performance dashboards * Align stakeholders across multiple teams and functions, balancing growth, reliability, compliance, and user experience * Act as the subject matter expert for payments and subscription platform topics within the product organisation #LI-Hybrid #LI-AJ1 Annual Salary Range (ranges may vary based on skills and experience) £92,000—£115,000 GBP How we work We’re a mission-led, product-driven team. We move fast, stay focused and take ownership – from brief to build to impact. Debate is encouraged. Decisions are shared. We care about craft, ship with purpose, and always raise the bar. You’ll be working with people who take their work seriously, not themselves. It takes commitment, resilience, and the drive to keep going when things get tough. Because better health outcomes are worth it.  What you'll get We support impact with meaningful reward. Here’s what that looks like: * Competitive salary and annual reviews * Opportunity to participate in Flo’s performance incentive scheme * Paid holiday, sick leave, and female health leave * Enhanced parental leave and pay for maternity, paternity, same-sex and adoptive parents * Accelerated professional growth through world-changing work and learning support * In-person collaboration and work in a hybrid model, with 3 days per week spent in the office * 5-week fully paid sabbatical at 5-year Floversary * Flo Premium for friends & family, plus more health, pension and wellbeing perks Diversity, equity and inclusion Our strength is in our differences. At Flo, hiring is based on merit, skill and what you bring to the role – nothing else. We’re proud to be an equal opportunity employer, and we welcome applicants from all backgrounds, communities and identities. Read our privacy notice for job applicants.

500M+ downloads. 80M+ monthly users. A decade of building – and we’re still accelerating. Flo is the world’s #1 health & fitness app worldwide on a mission to build a better future for female health. Backed by a $200M investment led by General Atlantic, we became the first product of our kind to reach a $1B valuation in 2024 – and we’re not slowing down. With 7M paid subscribers and the highest-rated experience in the App Store’s health category, we’ve spent 10 years earning trust at scale. Now, we’re building the next generation of digital health – AI-powered, privacy-first, clinically backed – to help our users know their body better. The job As Senior Product Manager for Predictive Growth at Flo, you'll own Flo's predicted Lifetime Value (pLTV) platform across iOS, Android, and Web. pLTV is the shared signal behind UA bidding, budget allocation, creative-testing prioritisation, finance forecasting, and roadmap decisions across the organisation — making it one of the highest-leverage PM roles in growth. You'll work with a team of data scientists, machine learning engineers, and data engineers running Flo's production pLTV models across short-horizon (intra-day) and long-horizon (M15+) predictions. You'll drive accuracy improvements, expand signal coverage across platforms, and extend pLTV's reach into new decision domains. You'll also help scale Flo's in-house agentic experimentation system — already delivering 30%+ quality gains — and contribute to the next generation of Flo's marketing measurement stack, including Marketing Mix Modeling and incrementality testing. This is a senior IC role with company-wide visibility, partnering with leadership across User Acquisition, Finance, Analytics, and Engineering. It's equally hands-on in delivery: co-leading the team day-to-day with your engineering manager pair, writing the specs, defining the epics, staying close to the work. Your Experience Must have: * Proven experience owning machine-learning or data-driven products in production — predictive scoring, propensity, ranking, forecasting, or similar data-rich products. Strong fit for current Product Managers; also open to Engineering Managers, ML Engineers, or tech leads who have shaped product direction end-to-end and are ready to make the switch into a PM seat. * Hands-on delivery instincts — equally comfortable in Jira (writing specs, defining epics, refining the sprint backlog, unblocking the team) as in strategic planning and stakeholder management. Co-leads the team day-to-day with your engineering manager pair. * Hands-on partnership with data science and machine-learning engineering teams — partnering on model evaluation, retraining cadence, feature decisions, and release discipline. * Strong analytical fluency — SQL proficiency, comfort interpreting model evaluation metrics, and the habit of interrogating performance at segment, cohort, and campaign level rather than blended aggregates. * Demonstrated ability to influence senior cross-functional stakeholders across marketing, finance, analytics, and engineering — translating technical model behaviour into commercial decisions. * Comfortable in fast-paced, ambiguous environments — balancing platform investments against fast-cycle experimentation, with shifting priorities and competing demands. Nice to have: * Working knowledge of mobile and web user acquisition — how bidding, attribution, and campaign optimisation actually work, including privacy frameworks such as SKAN/ATT or Privacy Sandbox. * Hands-on experience with mobile attribution platforms (AppsFlyer, Adjust, Branch, Firebase) and modern measurement frameworks (SKAdNetwork, GA4). * Exposure to Marketing Mix Modeling, incrementality testing, holdout design, or causal inference techniques. * Familiarity with feature stores (Databricks, Tecton, Feast) and modern MLOps tooling. * Subscription-app, health & wellness, or femtech domain background. * Exposure to agentic AI or LLM-orchestrated workflows for ML experimentation, research, or model evaluation. What you'll be doing You'll be responsible for: * Owning Flo's pLTV product roadmap end-to-end across iOS, Android, and Web — driving accuracy improvements, expanding feature coverage, extending prediction horizons, and pushing pLTV into new decision domains (creative testing, product roadmap, pricing, hypothesis validation) alongside its existing UA and Finance use cases. * Partnering with data scientists and engineers on feature strategy — deciding which inputs the model consumes and ensuring those features are available reliably in production. * Operating rigorous release discipline — gated rollouts, shadow-mode evaluation, drift detection, automated retraining, and post-launch calibration — so production models stay accurate as data distributions and platform policies evolve. * Working closely with data scientists and analysts to investigate model quality issues — country-level miscalibration, cohort drift, signal anomalies — and feeding findings back into the next iteration. * Helping scale Flo's agentic ML experimentation system from hundreds toward thousands of model runs — compounding quality gains back into production. * Acting as the primary product partner to User Acquisition leadership — translating model behaviour into bidding decisions, framing trade-offs, and aligning on attribution-window strategy. * Reporting model performance and strategic recommendations into monthly leadership reviews and quarterly investment decisions. * Contributing to Flo's next-generation measurement stack — including Marketing Mix Modeling, incrementality testing, and causal lift methodology — so marketing investment decisions are grounded in causal, not correlational, signal. #LI-Hybrid #LI-AJ1 Annual Salary Range (ranges may vary based on skills and experience) £92,000—£115,000 GBP How we work We’re a mission-led, product-driven team. We move fast, stay focused and take ownership – from brief to build to impact. Debate is encouraged. Decisions are shared. We care about craft, ship with purpose, and always raise the bar. You’ll be working with people who take their work seriously, not themselves. It takes commitment, resilience, and the drive to keep going when things get tough. Because better health outcomes are worth it.  What you'll get We support impact with meaningful reward. Here’s what that looks like: * Competitive salary and annual reviews * Opportunity to participate in Flo’s performance incentive scheme * Paid holiday, sick leave, and female health leave * Enhanced parental leave and pay for maternity, paternity, same-sex and adoptive parents * Accelerated professional growth through world-changing work and learning support * In-person collaboration and work in a hybrid model, with 3 days per week spent in the office * 5-week fully paid sabbatical at 5-year Floversary * Flo Premium for friends & family, plus more health, pension and wellbeing perks Diversity, equity and inclusion Our strength is in our differences. At Flo, hiring is based on merit, skill and what you bring to the role – nothing else. We’re proud to be an equal opportunity employer, and we welcome applicants from all backgrounds, communities and identities. Read our privacy notice for job applicants.