Senior Fullstack Engineer (User Retention & App Ecosystem)

Join Kikoff, a leading fintech company, as a Senior Fullstack Engineer. In this role, you will focus on user retention and app ecosystem integration, driving user-facing projects and improving existing core services. You will be the technical owner for 1 to 2 large product areas and enhance observability, reliability, and operational excellence across existing services. The position offers a range of benefits, including health benefits, flexible PTO, and 401k matching.

• Lead and implement data-driven and impact-focused projects around user-retention and ecosystem integration end-to-end, affecting millions of users.
• Be the definitive technical owner for 1 to 2 large product areas across credit report retrieval, credit disputes, customer off-boarding experience, and cross-app integration.
• Enhance observability, reliability, and operational excellence across existing services.

• 6+ years of industry experience, or high-slope growth, with demonstrated breadth and depth of product impact
• Strong fullstack development experience with a backend focus: proficient or highly proficient on the backend, and experienced in either web frontend (React) or mobile (Flutter preferred)
• B.A. / B.S. / M.S. or strong self-taught fundamentals in computer science
• Strong system design skills for both new and existing systems
• Good judgment in identifying and choosing trade-offs between business impact, delivery speed, and long-term operational excellence
• Strong cross-functional communication and coworking skills with product, data, design, and legal partners
• Demonstrated ability to own and drive complex projects end-to-end, coordinating focused teams through ideation, requirements, design, implementation, launch, and post-launch
• Experience with financial infrastructure or regulated environments (credit bureau data, PII, SOC2)
• Background in fintech, payments, or lending infrastructure
• Experience integrating third-party APIs reliably and communicating with technical vendors
• Experience with classical ML model training and production deployment
• Experience with using business metric focused A/B tests and experiments for new features
• Experience in leveling up the team through code reviews, design docs, and technical guidance
• Thoughtful use of AI tools to accelerate delivery while maintaining operational excellence
• Eagerness for product and feature ideation
• Experience with our stack is a plus: Ruby on Rails, React, Flutter, MySQL
• Experience with observability, monitoring, and alarms in customer-facing systems
• If you like owning both the work and the outcome of a complex project end-to-end, we’d like to talk to you!