Senior Fullstack Engineer - User Retention & App Ecosystem

About the team

The User Retention and App Ecosystem team focuses on sustainable, long-term, and interconnected customer growth at Kikoff. We help customers stay around longer and get more value from their subscriptions. We ensure that customers are excited to explore the different consumer fintech apps across Kikoff’s growing ecosystem, with as little cross-app friction as possible.

We’re looking for a Senior Fullstack Engineer to drive user-facing projects, improve existing core services, and own product domains. If you like owning both the work and the outcome of a complex project end-to-end, we’d like to talk to you!

What you’ll be doing

1. Lead and implement data-driven and impact-focused projects around user-retention and ecosystem integration end-to-end, affecting millions of users.
2. 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.
3. Enhance observability, reliability, and operational excellence across existing services.

What we’re looking for

1. B.A. / B.S. / M.S. or strong self-taught fundamentals in computer science
2. 6+ years of industry experience, or high-slope growth, with demonstrated breadth and depth of product impact
3. 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)
4. Strong cross-functional communication and coworking skills with product, data, design, and legal partners
5. Demonstrated ability to own and drive complex projects end-to-end, coordinating focused teams through ideation, requirements, design, implementation, launch, and post-launch.
6. Good judgment in identifying and choosing trade-offs between business impact, delivery speed, and long-term operational excellence
7. Strong system design skills for both new and existing systems

An ideal candidate also shows

• 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 observability, monitoring, and alarms in customer-facing systems
• 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