Full-Stack Engineer ( + equity) AI Growth Infrastructure

About the job

This role is being recruited by CoffeeSpace on behalf of a YC- and Google-backed AI startup building self-improving software for consumer apps.

We’re identifying a small number of exceptional full-stack engineers from our network.

If there’s a strong fit, we’ll introduce you directly to the founding team.

Location: San Francisco, CA, in-office Monday to Friday

Compensation: $150k–$250k base + 0.5%–1.5% equity

Employment type: Full-time

About the company

This company is building AI that automatically generates, tests, and learns from new product experiences to help consumer apps grow revenue.

The platform powers monetization flows such as onboarding, paywalls, and subscription conversion experiences, then continuously experiments and improves them based on real user behavior.

The company is already working with major consumer apps, serving tens of millions of AI-generated experiences per day, and growing quickly.

They have raised $6M from YC, Google’s AI fund, and leading operators, and are on track toward $1M ARR with revenue doubling monthly.

The team is small, intense, and highly technical: 8 people, mostly engineers, with a strong concentration of ex-founders and ML backgrounds.

The role

You’ll join as one of two founding full-stack engineering hires and own large parts of the AI Experience Generation product.

This is not a narrow frontend role or a narrow backend role. You’ll work across the stack: shipping product features in Next.js, building scalable Golang systems, designing data infrastructure, and helping the platform scale from tens of millions to hundreds of millions of daily AI experiences.

You’ll be given problems, not tickets. You’ll be expected to propose solutions, write quick specs or PRDs, ship, test, and validate your work against real users.

You’ll work directly with the founders, customers, and engineering team on product decisions that affect millions of end users.

What you’ll do

• Build and ship full-stack product features across Next.js, React, TypeScript, Golang, and modern cloud infrastructure
• Develop systems that serve thousands of requests per second globally
• Tune, optimize, and load-test servers as the company scales toward hundreds of millions of AI experiences per day
• Design data systems and ML training infrastructure that power automated experimentation
• Work directly with founders and customers to design, implement, and validate new product experiences
• Own features end-to-end: write specs, ship production code, test performance, and measure user impact

Who this is for

You may be a strong fit if you have:

• 0–7 years of software engineering experience with real full-stack range
• Backend experience with Python, Go, AWS, or similar infrastructure
• Frontend experience with TypeScript, JavaScript, React, Next.js, or a modern equivalent
• One of the following signals: ex-founder, early engineer at a startup, tier-1 engineering team background, elite CS school, meaningful open-source work, strong side projects, or other clear evidence of exceptional ability
• Comfort with high-ownership, fast-moving, in-person startup environments
• Authorization to work in the US without new visa sponsorship

Nice to have

• Experience building 0→1 products or features from scratch
• Early-stage startup experience, especially as an early engineer
• Production experience with LLM APIs, prompting, RAG, agents, evals, or AI workflows
• Data pipeline, ingestion, analytics, queueing, async job, webhook, or workflow system experience
• Evidence that you build outside of work: OSS, technical writing, Show HN posts, side projects, or real-usage products

This role is probably not for you if

• You want pure ML research, model training, data science, or infrastructure-only work
• You are a pure frontend or pure backend specialist and do not want to work across the stack
• You are looking for a Staff, Principal, Architect, or management-track role
• You prefer highly scoped tickets over ambiguous product and engineering problems
• You want a slower-paced or remote-first environment

Why this role is remarkable

• You’ll join a company with real traction, real scale, and a very small team.
• The product already serves tens of millions of AI experiences per day, revenue is growing quickly, and the engineering problems are not theoretical. You’ll be building systems that directly affect conversion, retention, and revenue for large consumer products.
• This is a strong fit for someone early in their career but unusually high-slope: someone who can build across the stack, think from first principles, talk to customers, and own meaningful product surface area without waiting to be told exactly what to do.

Next steps

• Apply via this LinkedIn job post.
• We’ll review and reach out if there’s a strong match.
• If aligned, we’ll introduce you directly to the founding team.
• If this role is not the right fit, we may suggest and make introductions to other high-signal startup roles we’re actively recruiting for, always with your permission.

A quick note on authenticity

This is a real, active role CoffeeSpace is recruiting for in close partnership with the hiring team. We do not post speculative roles and work directly with teams on their actual hiring needs.