Technology

Senior Fullstack Engineer - User Retention & App Ecosystem

KikoffSan Francisco🇺🇸United StatesPosted Oct 9, 2026

Why this role stands out

This hybrid Senior Fullstack Engineer role at a rapidly growing, pre-IPO fintech company offers a competitive salary and the chance to significantly impact the financial security of millions. You'll thrive here if you enjoy end-to-end ownership of complex projects, driving user retention, and building innovative solutions within a collaborative team environment. Apply now to contribute to meaningful work and grow your career in a dynamic space.

Quick overview

Salary$244k - $292k/yr

SeniorityMid Senior

Work modeHybrid

LocationSan Francisco, United States

Posted2 weeks ago

MySQLRubyFlutterRailsReactSystem Design

Job description

Kikoff: The Fintech Powering Financial Security at Scale
Kikoff is a profitable, pre-IPO fintech company on a mission to empower everyone to achieve financial security. With record revenue growth in 2025 and a unicorn valuation, we've built a suite of products that help millions of people build credit, access liquidity, and save money.
We're scaling fast. Join us if you want to build something meaningful and help millions of people move forward financially.

Why Kikoff:

This is a consumer fintech startup, and you will be working with serial entrepreneurs who have built strong consumer brands and innovative products. We value extreme ownership, clear communication, a strong sense of craftsmanship, and the desire to create lasting work and work relationships. Yes, you can build an exciting business AND have real-life real-customer impact.

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

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.

What we’re looking for

B.A. / B.S. / M.S. or strong self-taught fundamentals in computer science
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)
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.
Good judgment in identifying and choosing trade-offs between business impact, delivery speed, and long-term operational excellence
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

Base Range

$244,000—$292,000 USD

A note on applying: We know great candidates sometimes hold back if they don’t meet every qualification listed. If you’re excited about this role and believe you can do the work, we encourage you to apply. We’re looking for capability and trajectory, not a perfect checklist match.

Equal Employment Opportunity Statement

Kikoff Inc. is an equal opportunity employer. We are committed to complying with all federal, state, and local laws providing equal employment opportunities and considers qualified applicants without regard to race, color, religion, creed, gender, national origin, age, disability, veteran status, marital status, pregnancy, sex, gender expression or identity, sexual orientation, citizenship, or any other legally protected class.

Please reference the following for more information.