Founding Engineer

Headcount 1

Job Details

• Experience 0 -3 Years
• Salary $ - $
• Equity Competitive Equity
• Visa Sponsorship None Available
• Employment Type Full-Time position
• Work Type In-person

Benefits & perks

• Free lunch and dinner ($35 stipend on Uber Eats / DoorDash)
• Office gym
• Direct working relationship with the founding team
• High-impact founding seat at the ad network for AI

About this role

We are hiring a Founding Engineer to own the brain of the ad network: the engine that decides, in real time, which ad reaches which user at which moment across millions of daily interactions. This is a founding role spanning data pipelines, models, and production serving, with direct business impact at every layer. You’ll report to the Co-Founder and work closely with the founders and the rest of the small engineering team. This role is in person at our San Francisco office, 5 days a week.

The search is profile-driven rather than tech-stack driven. We are looking for a true generalist with genuine technical depth: someone comfortable across infrastructure that serves millions of users, classical ML models, and AI agents, who reasons about systems from first principles rather than assembling off-the-shelf AI tooling. You’ll inherit a working rec stack with real traffic and real open problems (delayed rewards, fatigue modeling, cold start), and help define the approach. AdTech experience is a plus, not a requirement; being a gamer matters more. US persons only (citizens or green card holders); no visa sponsorship.

What You'll Own

• Recommendation engine: design and ship a low-latency ad ranking system (retrieval, ranking, reranking) that selects the optimal campaign and creative, including playable game ads, for each ad opportunity, balancing advertiser ROAS against user experience
• ML training infrastructure: architect the data pipelines and feature stores that power continuous model training across reward signals on very different clocks: clicks (seconds), installs (hours), conversions (days)
• User and context modeling: build representations of user behavior from conversational data, engagement history, and contextual signals (geo, device, session context, characters interacted with) to power personalization
• Serving infrastructure: build the stack for sub-second latency and cost efficiency under tight per-impression unit economics
• Generative ad agents: build agents that generate and ship playable and video ad variants on the fly, feeding performance back into the recommendation engine

What's Already Live

The hire inherits a working system with real traffic, not a blank slate.

• The rec stack this role owns, already serving ads across millions of daily interactions: 30M+ users reached and millions of dollars in annualized ad spend
• Dozens of AI-generated playable mini-game and video ads running in production inside major AI apps, built on our own playable engine and editor
• Our own ad SDK (Swift, Kotlin, React, React Native), live in top App Store and Google Play apps

The Team

A small team in San Francisco with 3x exits and experience from Google, Blackstone, Bain Capital, PayPal, and DraftKings. Backed by a16z. The Founding Engineer gets ownership, equity, and a direct line to what ships.

Requirements

• Shipped ML or AI system in production
• Backend, data pipelines, and serving infra
• Active builder (GitHub or side projects)
• High agency, ships fast
• Explains clearly and concisely what they built and why

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