Full-Stack Engineer

About

About Helium

Helium is building Self-Improving Software: AI that automatically generates and tests new product experiences to lift revenue. The product helps consumer apps like Calm, Whisprflow, and Locket convert more users to subscriptions and retain them. Helium manages monetization experiences, pings customer apps in real time, and automatically generates AI-driven onboarding and paywall variants. The team is 8 people (5-6 engineers, 75% ex-founders, all 3 cofounders have ML degrees). Raised $6M from YC and Gradient (Google's AI fund), with leaders from OpenAI. Currently $80K MRR doubling monthly, on track to $1M ARR with Series A this summer. Serving tens of millions of AI experiences per day.

About the role

Helium is hiring 2 full-stack engineers to own big chunks of the AI Experience Generation product serving millions of users daily. You'll add features to the Next.js frontend, ship scalable Golang code serving thousands of requests per second globally, tune and load-test servers as the team 10x's user volume from tens to hundreds of millions per day, and design data systems plus ML training infrastructure that power automated experimentation at scale. The team is not prescriptive about engineers: you'll be given problems and expected to propose solutions and execute them. Pure backend or pure frontend specialists are not the target right now. You'll write your own PRDs/quick specs, talk to customers, and own features end-to-end. Reports to Shishir (CTO, ex-Alexa ML Infra). In-office Monday-Friday, with weekend pushes common.

What you'll own

• Ship features on the Next.js / Golang AI Experience Generation product serving tens of millions of users daily
• Tune, optimize, and load-test servers as Helium 10x's volume to hundreds of millions of users per day
• Design data systems and ML training infrastructure that power automated experimentation at scale
• Work directly with founders and customers (Calm, Whisprflow, Locket, comparable) to design, implement, and deliver new experiences
• Own features end-to-end: write PRDs/specs, ship, test, and validate against real users

Requirements

Must-have

• 0-7 years of software engineering experience with a full-stack range (both backend and frontend)
• Backend experience (Python, Go, or infrastructure like AWS) AND frontend experience (TypeScript/JavaScript/React or modern equivalent)
• One of the following: 1.5+ YOE at a Tier-1 engineering team (FAANG, YC company, scale-up), ex-founder background, CS degree from an elite school (Ivies, Waterloo, well-respected state schools), or other evidence of greatness (side projects, OSS, etc.)
• Open to moving to SF and working Monday-Friday in the office with frequent weekend pushes
• US citizen or visa holder. No $100K H-1B.

Nice-to-have

• Built or owned 0→1 product/features from scratch
• Early engineer at a startup (roughly #1-15) or worked at an early-stage startup / small product team
• LLM APIs shipped in production: prompting, RAG, agents, evals, AI workflows
• Data pipeline/ingestion/analytics infra experience (queues, async jobs, webhooks, ETL/ELT, workflow systems)
• Builds in public: writing, OSS, talks, Show HN, meaningful GitHub

Benefits & perks

• All meals (breakfast, lunch, dinner) in office
• Gym membership at nearby gym
• Quarterly off-sites
• Build on the newest AI models even before public release
• Real ownership: 0.50%-1.50% equity for founding-tier engineers

Interview process

1. 1Application review
2. 2Initial Screen
3. 3Technical Screen
4. 4On-Site
5. 5Work Trial
6. 6Offer Extended
7. 7Hired