Software Engineer - Platform

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 of the marketplace. 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 The Role We are looking for strong engineers with experience and interest in designing, building, and maintaining the infrastructure that make up our adtech platform. You might be a fit if - You have maintained or operated serious systems in production at scale - You are detail-oriented and care about performance - You enjoy diving deep into problems and owning the platform layer that powers our product - You enjoy experimentation, measuring, and creating reliable systems - You want to own a breadth of systems