Founding Sr Full-Stack Engineer

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

• Tailwind/Shadcn

• Supabase

• Clickhouse

• Golang/ Fly.io

• Mobile: Swift, Flutter, Expo, Android

• Requires Bachelors degree or higher in Computer Science or similar fields.