Join a high-growth consumer platform reaching #4 in the App Store with only three employees. You will own the full-stack architecture and personalized recommendation infrastructure serving 2T tokens monthly. This is a rare opportunity to build the future of entertainment alongside founders from Substack and world-class AI researchers in San Francisco.
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Founding Engineer at Y/n
Join an elite team of three serving 2 trillion tokens monthly at one of the world's top-ranking book apps. Backed by $14M from Sequoia and Kleiner Perkins, this startup is redefining entertainment with interactive stories where 100K+ teens spend hours daily. As a Founding Engineer, you will own the app surface and recommendation engine, building alongside the founding designer of Substack and a pioneering AI researcher. If you want to scale a product reaching #4 on the App Store and help architect the future of fandom, this San Francisco-based role offers massive ownership and equity.
About this role
Role overview
About the company
Y/n
$14M Sequoia and Kleiner Perkins backed interactive storytelling startup
What you'll do
What you will do
- Take end-to-end ownership of the core app surface and critical product features used by millions of global users.
- Design and scale personalized recommendation systems to handle high-concurrency traffic and massive token distribution.
- Architect and maintain robust infrastructure that goes far beyond simple deployments to support complex, interactive story engines.
Who you are
Who this is a fit for
- Proven track record of building and scaling production infrastructure rather than just managed deployments.
- Previous experience in a high-growth startup environment or a portfolio of deeply technical and meaningful side projects.
- A genuine passion for fandom, reading, or fanfiction culture to help shape the next century of digital storytelling.
Why this role
Why this role is remarkable
- Exceptional traction with 100K+ teenagers spending 3+ hours daily in-app and 40% MoM growth in user engagement.
- Elite pedigree working directly with the founding designer of Substack and a CTO who trained the world's first image-editing AI.
- Massive technical scale serving over 200 million user messages per month with a lean, world-class engineering team.
Jack & Jill
How Jack & Jill work together
I get to know what you’re great at, then find roles you’d never find yourself.Ok, I'll go first. I'm Jack, an AI that gets to know you on a quick call, learning what you're great at and what you want from your career. Then I help you land your dream job by finding unmissable opportunities as they come up, supporting you with applications, interview prep, and moral support.
I recruit from Jack’s network and make the intro when I spot a great match.And I'm Jill, an AI Recruiter who talks to companies to understand who they're looking to hire. Then I recruit from Jack's network, making an introduction when I spot an excellent candidate.
Meet Jack
Jack gets to know what you're great at and what you want next, then searches 15 million jobs daily and helps you discover roles at companies like this.
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