Senior Founding Engineer - AI Start-up - NYC

Senior Founding Engineer | Build the Future of Agentic AI | NYC Start-Up

The Opportunity

Engineer #2. equity. A top-tier Silicon Valley VC behind you. And an AI platform that's doubling its customer base every month.

This is a chance to get in at the ground floor of a company building something genuinely ambitious.

We're working with an incredibly exciting, VC-backed NYC start-up developing an agentic AI platform that runs the growth operations of consumer brands. Think AI that doesn't just analyse performance or make recommendations, but actually understands what drives growth, makes decisions and takes action.

They're now looking for a Senior Founding Engineer to help build the technology powering it all.

You'll be the second engineer in the business, working directly with the CEO and an existing founding engineer.

You'll have enormous ownership over the technical direction, architecture and engineering culture, while remaining deeply hands-on and shipping from day one.

This is a genuine 0→1 opportunity, with the chance to build something from the ground up and grow with a business that's already gaining serious traction.

What You'll Build

• The intelligence layer: Design and build the data infrastructure that captures every event across a merchant's lifecycle, connecting actions to outcomes and giving the platform the intelligence to continuously improve.
• Autonomous growth agents: Develop sophisticated agentic systems that assess a brand's growth operations, identify opportunities, make decisions and execute strategies automatically.
• The core growth engine: Own the backend-heavy full-stack architecture powering the platform, from data pipelines and orchestration to production-ready AI systems.
• Real-world integrations: Build and scale integrations with Shopify, Meta and TikTok, connecting directly into the platforms where consumer brands operate.
• The engineering foundation: Set technical standards, make key architectural decisions and help shape the engineering culture as the team grows.
• Lead by building: Mentor the existing founding engineer while staying hands-on with the code every day.

What They're Looking For

You're a strong full-stack engineer with a serious backend bias. You enjoy solving complex engineering problems, building systems from scratch and taking complete ownership of what you ship.

You'll ideally bring:

• 3+ years of full-stack engineering experience with strong backend and infrastructure experience.
• Experience building data-intensive systems, event-driven architectures and complex API integrations.
• Hands-on experience building and deploying agentic AI or LLM-powered systems in production.
• Experience owning products or systems end to end, from initial architecture through to production.
• Some experience mentoring or leading other engineers, whether formally, as a tech lead or in an early-stage environment.
• The ability to move quickly, make decisions and bring structure to an environment where not everything is already defined.

You've ideally worked in a high-growth technology business, a well-funded start-up or come from a strong engineering programme.

The stack: Python, TypeScript, LLMs, Shopify, Meta and TikTok Ads APIs, Klaviyo. They're language-agnostic and more interested in engineering ability than matching every technology.

Founding-engineer experience, 0→1 product development and commerce or MarTech integrations would be a big advantage.

Why This Opportunity?

• Engineer #2: Get in exceptionally early and help build the engineering function from the ground up.
• 1%+ equity: Meaningful ownership in a company with serious growth ambitions.
• Real agentic AI: Build autonomous systems that take action, execute growth strategies and deliver measurable outcomes for real businesses.
• Direct CEO exposure: Work directly with the founder and influence the biggest technical and product decisions.
• Serious momentum: Join a business doubling its customer base every month, with top-tier Silicon Valley investors backing its vision.
• Room to build: Shape the architecture, culture and future engineering team rather than simply inheriting someone else's decisions.

The Company

An early-stage, VC-backed AI start-up based in New York, building at the intersection of agentic AI, e-commerce and consumer brand growth.

Small team, ambitious vision and a huge amount of scope for someone who wants to make an impact.

The Details

Location: NYC – hybrid, 4 days per week in the office.

Relocation: Open to candidates relocating to New York.

Visa: Open to visa transfers, including OPT and H-1B transfers.

Compensation: $175,000–$225,000 + 1%+ equity.

If you want to be more than another engineer joining an established team, this is your chance to become one of the people building the company itself.

Build the technology. Shape the team. Own a meaningful piece of what comes next.