hirly

Koahlabs

Software Engineer - Backend

San Francisco

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Role family
Engineering
Seniority
Mid level
Country
US
Work mode
On-site / unstated
First seen by hirly
1 Sept 2026

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the posting

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

Example projects

Build scalable data models that support multiple impressions for an ad request allowing us to align publisher and advertiser interests

Design abstractions that allow us to experiment and ship new formats that allow for a flexible way of tracking engagement events

Build a low-latency frequency capping system to improve an end user's experience and prevent ad fatigue

Create schemas to represent high-volume ad bidding with ad exchanges to increase the diversity of the ad demand on platform

Evolve our real-time auction and ad-decisioning systems to improve publisher, advertiser, and user outcomes

You might be a fit if

You like debugging and optimizing performance

You are detail oriented and like to create good abstractions that others rely on

You enjoy experimentation, measuring, and creating reliable systems

You want ownership of foundational systems

You enjoy working closely with product and data science to turn ambiguous problems into measurable outcomes

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Software Engineer - Backend at Koahlabs — hirly