Software Engineer - Platform at Koah (San Francisco, CA)

Koah· San Francisco, CA· $180k–$250k·2d ago

Role details

Salary

$180k–$250k

Work type

Onsite

Employment

Full-Time

Skills

TerraformAWSPostgreSQLClickHouseRedisKafkaPythonRuby on RailsReactTypeScriptFlutterReact Native

Benefits

Equity

Summary

Koah is seeking a Software Engineer to design, build, and maintain the infrastructure for its adtech platform. The role involves operating systems at scale, focusing on performance, reliability, and owning the platform layer that powers the product.

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 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

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.

About Koah

Company Overview

One-liner: Koah builds the ad infrastructure for AI-native applications, enabling publishers to monetize AI chat and agent experiences with contextual, sponsored placements.
Entity Type: Private (Seed Stage)
Headquarters: San Francisco, California, United States
Founded: 2024
Founders: Nic Baird (CEO), Mike Choi, Herrick Fang

Core Business

Primary Industry: Advertising Technology (AdTech) / Generative AI Infrastructure
Target Customers: B2B — serves both AI app publishers (developers and companies building AI chat/agent experiences) and advertisers (brands seeking high-intent, context-aware ad placements).
Mission/Purpose: To create the essential monetization layer for consumer AI services, making it possible for AI-native apps to be profitable at scale without relying solely on subscriptions.

Products & Services

Koah Ad Network: A native advertising platform designed specifically for generative AI environments. Publishers embed a JavaScript snippet or SDK to serve contextual, sponsored content directly inside chat and agent conversations. Advertisers can reach users in moments where AI is shaping their decisions, with clickthrough rates reported at 7.5% (4x-5x higher than traditional display ads). Early partners have earned $10,000 in their first 30 days on the platform.

Market Standing

Total Funding: $25.5 million
- Seed Round (October 2025): $5 million led by Forerunner, with participation from South Park Commons and AppLovin co-founder Andrew Karam.
- Series A (February 2026): $20.5 million led by Theory Ventures.
Key Metric: Annual Revenue not publicly disclosed; early partners generating $10k in first 30 days.
Notable Investors/Partners: Theory Ventures (lead Series A), Forerunner (lead Seed), South Park Commons, Andrew Karam (AppLovin co-founder). Advertisers include UpWork, General Medicine, and Skillshare. Publisher partners include Luzia, Heal, Liner, and DeepAI.
Growth Signals: Headcount grew 633% year-over-year to 18 employees. Active job postings increased 66.7% quarterly. LinkedIn followers grew 744.8% year-over-year. The company is expanding its go-to-market team with a Founding Head of Ad Sales role.

Competitive Advantages

Native AI Ad Format: Unlike older adtech companies (AdMob, AppLovin) that try to retrofit display ads into AI, Koah builds ads that are contextually embedded within the conversational flow, making them additive rather than disruptive.
High Performance: Delivers 7.5% clickthrough rates (4x-5x better than traditional ads) with less detrimental effect on user engagement.
First-Mover in a Growing Market: As the "long tail" of AI apps built on top of large models expands, Koah positions itself as the essential monetization layer, solving the "elephant in the room" of how to make consumer AI profitable globally.
Strong Investor Backing: Backed by top-tier VCs (Theory Ventures, Forerunner) and a successful adtech founder (AppLovin co-founder), providing both capital and deep industry expertise.

Strategic Focus

Monetization Infrastructure for AI: Koah is focused on becoming the default ad network for the generative AI ecosystem, enabling "vibe coded" apps to operate at scale without requiring VC funding or subscription-only models.
Global Expansion: The company is targeting apps with user bases outside the United States, recognizing that subscriptions alone don't work for global audiences.
Product Development: Building out the SDK, API, and developer tools to make integration seamless for publishers, while refining ad targeting to capture "commercial intent" within AI conversations.

Sources