Koah

Applied Scientist at Koah (San Francisco, CA)

Koah· San Francisco, CA· $200k–$300k·

Role details

Salary
$200k–$300k
Work type
Hybrid
Employment
Full-Time
Skills
PythonPostgreSQLClickHouseRedisKafkaTerraformAWSRuby on RailsReactTypeScriptFlutterReact Native
Benefits

Equity

Summary

Koah Labs seeks an Applied Scientist to design algorithms for real-time bidding, build predictive regression models, and apply privacy-preserving clustering methods to improve ad matching and publisher monetization.

Job description

Who We Are

Koah Labs is building the ad network to power the next generation of AI-native products. Our mission is to help publishers monetize and help advertisers reach the right audience — without compromising speed, UX, or privacy.

We’re a small, tight-knit team in San Francisco with backgrounds at X, Apple, Meta, and early-stage startups. We’ve raised from top investors and are growing fast with real traction on both the publisher and advertiser sides.

Working at Koah means joining at the ground floor: you’ll ship code that shapes the company and the ecosystem we’re building. We move quickly, operate with high trust, and care deeply about craft.

Our Stack

  • Infra: Terraform, AWS, LGTM (Loki, Grafana, Tempo, Mimir), Tailscale, Cloudflare
  • Data: PostgreSQL, ClickHouse, Redis, Kafka, Python
  • Core Application: Ruby on Rails, React, TypeScript
  • SDKs: Flutter, React Native, Android, iOS

Example Projects

  • Design efficient algorithms for real-time bidding systems, building upon the current pricing literature
  • Create and productionize regression models to predict end conversions based on demographic, audience, and semantic data
  • Apply privacy-preserving clustering methods to categorize conversational data to improve advertiser outreach
  • Analyze and pore over data to find alpha that can improve the core ad matching system balancing publisher and advertiser outcomes

You might be a fit if

  • You have an advanced degree in Physics, Computer Science, Mathematics, Statistics, Engineering, or a related field
  • You enjoy identifying and owning challenging problems, forming testable hypotheses, and conducting impactful research to drive significant business impact
  • You have a relentless focus on continuous learning and making an impact with an ability to question the status quo
  • You have strong mathematical and statistical modeling skills
  • You enjoy communicating conclusions to both technical and non-technical audiences alike

Why work at Koah

  • High-Growth Environment: The company has grown headcount by 633% in the last year and is actively hiring across engineering, product, design, data science, and go-to-market roles.
  • Mission-Driven: Employees work on solving a fundamental problem for the AI ecosystem — how to make AI apps profitable without compromising user experience.
  • Culture Values: The company emphasizes "design for quality," "velocity over perfection," "experiment boldly," and "respect first." They value ownership, rapid iteration, and data-driven decision-making.
  • Work Policy: Hybrid/on-site presence in San Francisco and New York. The Founding Head of Ad Sales role is listed as on-site in San Francisco or New York.
  • Team Composition: Small, high-leverage team (18 people) with a flat structure. Technical roles (engineering, data science, product) make up a significant portion of the team.
  • Tech Stack: Modern stack including React, TypeScript, Python, PostgreSQL, ClickHouse, Redis, Terraform, Cloudflare, and Grafana — appealing to engineers who want to work with cutting-edge infrastructure.

Application questions