Founding Sr Full-Stack Engineer

About the role

Helium is building Self-Improving Software: AI that automatically generates & tests new software experiences to lift revenue. We’re…

- Talent-dense (8 people, 6 engineers, 75% ex-founders)

- Well-funded ($6M from Google & Leaders from OpenAI)

- Fast-growing (Serving tens of millions of AI experiences per day for top consumer companies).

AI has created a once-in-history opportunity, and we’re here to win, because of that…

- 🔴 We work hard — In-Office Monday–Friday + often push through weekends 🔴

What You’ll Do

You’ll own big chunks of our AI Experience Generation product serving millions of users per day, including…

- Adding new features to the front-end Next.js application and deploying scalable Golang code that serves thousands of requests each second globally.

- Tune/Optimize/Load test our servers as we 10x our growth from tens of millions to hundreds of millions of users per day.

- Designing data systems and ML training infrastructure that power automated experimentation at scale.

- Work directly with founders and customers to design, implement, and deliver the best experiences!

- Wearing a lot more hats than listed above 👷.

What We’re Looking For

- Keen problem solving skills: you are able to cut down ambiguous problems down to first principles and deliver a working solution.

- Strong programming/full-stack foundation: You’re comfortable working on both backend code as well as frontend React code.

- Experience working directly on user-facing products: you are able to figure out and understand what the user needs, including talking to customers

- Stellar cross-functional communication skills: you are able to adapt to our ways of working and be an efficient/effective communicator.

- Owning features end to end: you’ll write your own PRDs/quick specs when necessary, and you test your features end to end to make sure they work and satisfy the requirements

- Experience scoping, designing, and running complex multi-engineer projects

- Experience managing or mentoring engineers before

Nice To Haves

- Experience with ML/AI/LLM integration in applications

- Experience building scalable backend systems with very demanding SLAs

- Background working with design tools, chat experiences, or vibe coding tools

- Previous experience founding or working at a high-growth startup

Reasons This Role Might Not Be A Fit

- You want to work 9-5

- You avoid Cursor or AI coding tools.

- You can only operate on well-written specs, or feel uncomfortable designing new experiences from scratch.

- You don’t want to talk to customers.

Our stack:

- Next.js (React/Typescript), Zustand

- AI (vercel) SDK