Founding Data Scientist

Sela AI; San Francisco, Northern (CA, KY); Hybrid; USD 180,000 - 250,000; Full time

Benefits offered by this job

Medical Coverage (top-of-market)

Dental & Vision (top)

401(k) Matching (top)

Unlimited PTO

Snacks, team lunches & dinners

Job summary

Sela AI in San Francisco is seeking a Founding Data Scientist to help build the top‑performing AI sales agent for mortgage calls. You will design experiments, analyze hundreds of millions of calls, and translate insights into improvements for our real-time, multi-agent platform.

Join a fast-growing startup with equity, top-market health/dental/vision, 401(k) matching, unlimited PTO, and a hybrid in-office schedule four days a week in SF with a remote day on Wednesdays.

Qualifications

• 4+ years of experience in data science, machine learning, experimentation, or a closely related field.
• Strong statistical foundations and experience designing and analyzing experiments.
• Strong Python and SQL skills and the ability to work with very large datasets.
• Ability to take an ambiguous problem, figure out what to measure, and turn the results into actionable recommendations.
• Strong technical judgment and the ability to work closely with engineers on experimentation systems.
• High agency and the ability to operate without an established playbook.
• Experience designing experimentation or optimization systems at scale (nice to have).
• Experience with causal inference, personalization, ranking, or recommendation systems (nice to have).
• Experience working with LLMs, speech, or conversational data (nice to have).
• Experience at a fast-growing startup or as an early data science hire (nice to have).

Responsibilities

• Experimentation across hundreds of millions of sales calls, from identifying opportunities to measuring results.
• The methodology behind how we design experiments, measure outcomes, and make decisions.
• Turning insights from our calls into improvements to our AI sales agents.
• Ensuring our experimentation framework can support increasingly sophisticated experiments as we scale.
• As our first data scientist, defining how data science is done at Sela and eventually the team we build.

Skills

Python

SQL

Experimentation

Statistics

Data analysis

Job description

We're building the future of consumer finance.

LLMs are trained to follow the human they're talking to. Ours has to lead: read intent and tone, build trust, and guide complex conversations toward an outcome. Doing that naturally, responsibly, and at production scale requires systems frontier models weren't built to provide. That's what we're building.

Guiding borrowers through high-stakes financial decisions across hundreds of thousands of calls a day is not easy. Here's what you'd actually be building.

01 An LLM That Leads, Not Follows

• Models are trained to be agreeable. Ours has to guide the conversation.
• Read intent and tone, adapt in real time, and move a complex decision forward
• A research-flavored problem the labs aren’t optimizing for

02 Real-Time, Non-Deterministic

• What sounds like one agent is a swarm of specialists handing off mid-call
• We rewrite the agent’s context, tools, and instructions between turns
• All inside a few hundred milliseconds, every single turn

03 Testing Things With No Right Answer

• Conversations aren’t functions that return true or false
• Turn-level evals on real moments, plus full end-to-end simulations
• Simulated callers, LLM-as-judge, and metrics per behavior

04 Real People, Real Responsibility

• People tell our agents genuinely personal things. That is not abstract.
• Security and privacy are design constraints, not a checkbox
• Bounded autonomy — unsafe actions simply don’t exist for the agent

How We Hire

This might sound simple but it is rigorously enforced. Our employees are the soul of the company and we both demand and reward success.

01 Intelligence

Uncommonly bright. You can hold a messy problem in your head and make it simpler, approach problems from creative angles, and navigate ambiguous and novel situations with clarity and speed.

02 Communication

Writing, thinking, and exchanging views is at the heart of our decision making process. We judge by the quality of the idea and the evidence, not the pedigree of the person who is sharing it.

03 Team player

Everyone's contributions must be impressive and significant, but they also must be integral to the success of the company. A team victory rewards all.

Culture

What We Keep Coming Back To

These three values govern how we work.

01 A+ bots, or don't ship

We insist on human-level fluency. Every conversation should feel natural, capable, and polished.

02 Own a large piece

Our product has lots of surface area and we expect each of our employees to own a large part of it. Your time is your own; self-starters and problem solvers will be celebrated.

03 This is supposed to be fun

We work hard and we don't take ourselves too seriously. The intensity and velocity are infectious.

The Practical Stuff

Generous where it counts: top-of-market health, early equity, four days in SF, and dinner on us.

01 Medical

Top-of-market health coverage for you and your dependents.

02 Dental & Vision

Comprehensive dental and vision coverage for you and your dependents.

03 401(k) Matching

A top-of-market employer match on your retirement contributions.

04 Meaningful Equity

Real ownership in what we’re building, granted at an early stage.

05 Top Talent, Top Pay

We hire exceptional people to build together in San Francisco, and pay accordingly.

06 Unlimited PTO

Take the time you need. We mean it — please actually use it.

07 Snacks & Dinner

Snacks around the office, and dinner on us.

08 Hybrid In Office

Four days a week together in SF, with a flexible remote day on Wednesdays.

Open Roles

Come Work Here

We're hiring people who can own a large piece and still make the whole better. The product is already in market, the problems are hard, and the team is still small enough that you'll change what we build.

Founding Data Scientist

Location

Employment Type

Full time

Location Type

On-site

Department

Product

About Sela

Sela is the market-leading AI voice agent for mortgage lenders. Founded in 2024, we’ve grown like crazy (~$0->13M in 20 months), and currently count 5 of the 10 largest independent mortgage banks in the U.S. as enterprise customers. If we’re successful, the cost of owning a home in the US will become ~1% cheaper. We’ve raised $21M across our Seed and Series A from top investors.

Why this is a huge opportunity

Around 1% of the U.S. labor force works in phone sales, representing roughly $100B of annual salary, and the industry is poised at the brink of complete disruption. We are at the cutting edge of this economic transformation, one of the first companies creating real, durable economic value through applied AI.

Buying a house is the largest financial decision most people make in their lives, and homeownership is tied to many other purchases, including life insurance, homeowners insurance, alarm systems, home renovations, solar panels, and more. By owning the mortgage vertical, we will own the relationship with the consumer, allowing us to serve as the essential AI infrastructure for high consideration consumer sales.

Why Join

Crazy growth: The market pull is exhilarating - we’ve grown 10x in the past 12 months and more than 100x since our seed round, all without a dedicated sales or marketing team. Building something that people want so badly is the best feeling you can have in a startup.

Team and Culture: We are a high-agency team where the bar is high and everyone makes the people around them better. Collaboration and intensity are core team values: people truly care about their work and their coworkers. At the same time, we don't take ourselves too seriously.

Challenging problems: Outperforming human sales teams on half a million daily calls is not easy. Low-latency, real-time infra. 99.9% uptime. Enterprise-grade privacy and security. Advanced simulation and evaluation systems. Flexible A/B testing. AI scheduler and dialer. We own the whole stack and we do not compromise on quality.

Well-funded: We’ve raised $21M+ in total funding, most recently a $15M Series A in June 2026.

What will you do

Help us build the top-performing AI sales agent in the world.

Analyze hundreds of millions of calls to understand what drives better sales outcomes.

Design and run experiments across every part of the sales call — what we say, how we say it, when we call, and more.

Build models that help us personalize and optimize calls for each lead.

Turn large, complex datasets into recommendations that directly improve our AI agents.

Partner closely with engineering to build a robust, scalable, and future-proof experimentation framework.

What will you own

Experimentation across hundreds of millions of sales calls, from identifying opportunities to measuring results.

The methodology behind how we design experiments, measure outcomes, and make decisions.

Turning insights from our calls into improvements to our AI sales agents.

Ensuring our experimentation framework can support increasingly sophisticated experiments as we scale.

As our first data scientist, defining how data science is done at Sela and eventually the team we build.

What are we looking for

Must haves:

4+ years of experience in data science, machine learning, experimentation, or a closely related field.

Strong statistical foundations and experience designing and analyzing experiments.

Strong Python and SQL skills and the ability to work with very large datasets.

Ability to take an ambiguous problem, figure out what to measure, and turn the results into actionable recommendations.

Strong technical judgment and the ability to work closely with engineers on experimentation systems.

High agency and the ability to operate without an established playbook.

Nice to haves:

Experience designing experimentation or optimization systems at scale.

Experience with causal inference, personalization, ranking, or recommendation systems.

Experience working with LLMs, speech, or conversational data.

Experience at a fast-growing startup or as an early data science hire.

$180k - $250k + equity

Top-of-market medical, dental, and vision coverage for you and your dependents

401(k) with a top-of-market employer match

Unlimited PTO

Snacks, weekly team lunches, and dinner on Sela

Hybrid in-office schedule: four days a week together in SF, with a flexible remote day on Wednesdays