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, and early-stage startups. We’ve raised $5.7M 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.

Tooling

• Infra: Render (app + workers), AWS (RDS, S3, Kafka), Grafana for metrics and logs

• Data: PostgreSQL (primary), ClickHouse (analytics), Redis (caching & rate limiting)

• Core Stack: Ruby on Rails, React, TypeScript

• SDKs: Flutter, React Native, Android (Kotlin, Compose), iOS (Swift)

We’re looking for engineers who like digging into systems and making them fast, reliable, and easy to operate. You’ll help us deliver ads quickly, track performance accurately, and scale the platform as we grow. We’re building systems that will soon operate at the scale of modern analytics platforms — high-volume, low-latency, and deeply queryable.

Example projects

• Build data pipelines using Debezium to stream real-time changes from PostgreSQL to our OLAP database for analytics workloads

• Reduce p99 latency in critical write paths by optimizing SQL query execution plans, implementing robust retry mechanisms, and enforcing strict timeouts for third-party services

• Tune converstion and clickthrough rate metrics in our core ad matcher from analyzing impression and click data

• Enhance ad matching algorithms using regression analysis to identify data patterns and develop hypotheses for new predictive features that improve conversion likelihood

• Set up experiment tracking and observability with logs and custom metrics that make it easy for us to understand why certain ads are chosen

You might be a fit if

• You like debugging and optimizing performance

• You are detail oriented and use data to support your claims

• You enjoy digging deeply and owning the platform side supporting product

• You enjoy experimentation, measuring, and creating reliable systems

If you're interested, please send an email to careers@koahlabs.com with your full name, email address, and resume.