Senior Data Scientist

Kikoff•San Francisco, CA

About The Position

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. 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. Our job is to make sure every Kikoff product does three things: makes a clear and compelling promise to the customer, delivers on that promise reliably over time, and turns that durable value into a business healthy enough to fund the next product, in a way customers would agree is fair. Every metric we define, experiment we run, and model we build should trace back to one of those three. We're a Data organization of roughly 20 people across product data science, marketing data science, and data engineering. This role sits with the data scientists embedded in Kikoff's core credit-building products, working alongside a Marketing DS partner who owns acquisition measurement and a data engineering team that owns the shared tooling underneath all of us. You'll have people to learn from and people to bring along. You'll take on a product area within core Kikoff as its data lead, working day to day with the product, engineering, design, and lifecycle marketing leads for that area, and you'll sit in the Kikoff-wide conversations on roadmap and objectives. Two things we're asking of this hire beyond the product area. First, help set technical direction and best practices for data science across Kikoff: how we do experimentation, how we evaluate AI products, how we review each other's work. Second, help define how we work as AI agents become a core part of the analysis loop, from exploration to pipelines to experiment readouts. We're actively rebuilding our workflow around this and want someone who has opinions.

Requirements

Experience partnering with product, engineering, and marketing peers across the whole arc of the work: strategy, goal setting, approach, and execution, not just the analysis at the end.
A track record of defining metrics from scratch and getting a team to run on them, including for products where success was hard to pin down.
Designed and ran experimentation programs, including changes where clean randomization wasn't available.
Comfortable with quasi-experimental and causal inference methods, and clear about their limits.
Hands-on with production-quality SQL and Python. You build pipelines, analyses, and models yourself.
Experience building or working closely with models that drive decisions in a product, in any domain: ranking, fraud, forecasting, personalization, underwriting, detection, LLM applications. We care about the judgment, not the vertical.
AI tools are a core part of your daily analytical work and you can show how they changed the speed and quality of what you ship.
You drive decisions with data in front of senior audiences, including when the data doesn't support the plan.

Nice To Haves

Built or ran an evaluation program for an LLM-based product: judge design, validation against human labels, test-case construction from real failures.
Consumer fintech experience, especially products that expand access for un- and under-banked customers.
Built an experimentation or causal inference practice in an org that didn't have one.
Have taken a model from proof of concept to production, or shipped test and challenger models that changed a product decision.
Have mentored, onboarded, or managed the work of other data scientists.

Responsibilities

Lead the data work for a core Kikoff product area: set the questions worth answering, build the evidence, and drive what happens next. Sometimes the right call is not to act on a finding, and you'll make that case too.
Define and maintain the measurement system for your area across the whole customer journey (activation, engagement, credit outcomes, retention, revenue, unit economics), and contribute to the Kikoff-wide measurement framework alongside the other data scientists on the team. Where acquisition intersects with what you own, you'll work it jointly with Marketing DS rather than around them.
Own product experimentation for your area: design, guardrails, analysis, and the recommendation on rollouts, including the cases where a holdout isn't clean or the effect you care about (a customer's score) moves on its own schedule.
For AI product surfaces, own evaluation: decide what "good" means in checkable terms, build and validate automated scorers against human judgment, and turn what you find in real conversations into regression tests so the product can't quietly get worse. Keep the loop between error analysis and the eval set closed.
Build and evaluate models where they're the right tool: proof-of-concept and challenger models, offline evaluation, threshold decisions, and production monitoring with engineering. Production model lifecycle sits with engineering today; how we divide that work is still evolving and you'll have a voice in it.
Partner with product, engineering, design, and lifecycle marketing leads on roadmap and objectives: which bets, what a win looks like, and what we'd need to see to stop.
Raise the bar for the people around you: review work, onboard new teammates, and take on an intern or early-career data scientist when the timing fits.