Fullstaсk Engineer

About this role

We're looking for a Full Stack Engineer to join Helium, a startup building Self-Improving Software – AI that automatically generates and tests new software experiences to lift revenue. Backed by $6M from Google and leaders from OpenAI, Helium serves tens of millions of AI experiences per day for top consumer companies, with a team of 8 (6 engineers, 75% ex-founders).

You will

• Own big chunks of the AI Experience Generation product, serving millions of users per day.
• Add features to the front-end Next.js application and deploy scalable Golang code serving thousands of requests per second globally.
• Tune, optimize, and load-test servers as the product 10x's from tens of millions to hundreds of millions of users per day.
• Design data systems and ML training infrastructure powering automated experimentation at scale.
• Work directly with founders and customers to design, implement, and deliver the best experiences.

Requirements

• Strong full-stack foundation comfortable working on both backend code and frontend React code.
• Experience working directly on user-facing products, including talking to customers.
• Experience owning features end-to-end – writing your own specs and testing to make sure requirements are met.
• Experience scoping, designing, and running complex multi-engineer projects.
• Prior experience managing or mentoring engineers.
• Bachelor's degree or higher in Computer Science or a related field.
• Stack
• Next.js (React/TypeScript), Zustand, AI SDK (Vercel), Tailwind/Shadcn, Supabase, ClickHouse, Golang/Fly.io.
• Mobile: Swift, Flutter, Expo, Android.

Nice to have

• Experience with ML/AI/LLM integration in applications.
• Experience building scalable backend systems with demanding SLAs.
• Background with design tools, chat experiences, or vibe coding tools.
• Previous experience founding or working at a high-growth startup.
• We offer
• Up to $250k/year + equity.
• Access to the newest AI models, often before public release.
• A hard-working team in a prime SF office.
• All meals covered while working, plus gym and transport.