Technical Co-Founder — San Francisco Bay Area

Technical Co-Founder / CTO — 9pXy

About 9pXy

9pXy is building the place where the next generation learns.

Millions of students already use iPads to study, but digital paper is still largely treated as a note-taking tool. We're building the learning platform around it, bringing together handwritten notes, curriculum, practice, assignments, and personalised AI tutoring.

Unlike traditional AI chatbots, 9pXy isn't designed to give students answers. It understands their handwritten work, marks their reasoning, identifies mistakes, and guides them towards understanding.

The ambition is to make 9pXy the learning infrastructure for students worldwide, starting with mathematics and expanding across STEM.

The role

I'm looking for a technical co-founder who wants genuine ownership of both engineering and the future of the company.

You'll take technical leadership of uKz8'6 existing product and help build the systems that make a fundamentally different learning experience possible.

What you'll work on

• Own and evolve uKz8'6 technical architecture across the iPad application, backend, and AI systems.

• Build reliable, low-latency AI tutoring systems that interpret handwritten work, evaluate reasoning, and deliver personalised feedback.

• Develop evaluation, verification, and optimisation systems to improve model accuracy, speed, and cost.

• Build the infrastructure for curriculum-based learning, adaptive practice, and personalised student experiences.

• Ship rapidly, experiment with new technologies, and help establish the engineering foundations for a company built to scale.

• Help shape the technical team, product strategy, and long-term direction of 9pXy.

Who I'm looking for

• A strong hands-on engineer with experience building and shipping real products.

• Comfortable taking technical ownership across multiple systems, with particular strength in backend engineering, applied AI, or native iOS development.

• Experience with Python, LLMs, model evaluation, or production AI systems is highly valuable.

• Someone who thinks deeply about product and user experience, not just implementation.

• Resourceful, independent, ambitious, and comfortable building in an early-stage environment.

• Someone genuinely excited about changing how people learn.

I care much more about what you've built and how you think than where you've worked or what degree you have.

The opportunity

This is a genuine co-founder partnership with meaningful equity and influence over the company's future.

We're currently operating lean, so there is no salary available before funding. I'm actively raising capital, with the intention of introducing salaries once financing allows. Equity and the terms of the partnership will be discussed openly.

If you're an exceptional builder who wants to create something used by millions of students, I'd love to hear from you.

• To apply: Tell me about something technically challenging you've built, what you personally contributed, and why building 9pXy interests you.