Founding Fullstack Engineer

Seamflow; Greater London; On-site; GBP 100,000 - 125,000; Full time

Job summary

A fast-growing tech startup in Greater London seeks a Fullstack Engineer to design and build end-to-end workflows. Candidates should have strong skills in TypeScript and React, and experience with Python for backend services. This role involves deploying features immediately and owning products from definition through to deployment, addressing real-world challenges, and integrating AI systems into workflow. The company offers a supportive culture focused on high standards and facilitates relocation if required.

Benefits

Visa sponsorship available

Relocation and meals fully covered

High trust, no politics environment

Qualifications

• Strong experience with TypeScript and modern frontend frameworks.
• Comfortable building backend services in Python.
• Experience integrating AI systems into production products.

Responsibilities

• Deploy to production immediately and own real product surface area.
• Create specs, figure things out, and build features end-to-end.
• Solve real problems from UX polish to backend logic.

Skills

TypeScript

React

Python

AI integration

Product engineering

User experience

Complex workflows

Job description

ABOUT THE JOB

We’re removing one of the last great barriers to progress in the physical world.
While software moves fast, industries like aerospace, healthcare, and energy are still slowed by outdated, manual systems.

We are rapidly growing in stealth with 6-figure revenue, backed by a 14× oversubscribed $4.5m seed round from Tier-1 VCs such as Coinbase, Reddit, Klarna, and Spotify. Our world-class team includes former unicorn founding engineers and talent from X, Google, Amazon, and Yandex. We value people who want to win and thrive in high-ownership environments.

We’re building the system that lets complex, real-world work move at software speed.

WHO WE ARE LOOKING FOR

We’re looking for a Fullstack Engineer who thinks in user workflows, not tickets or isolated features.

This is a role for someone who wants to decide what should exist, build it end-to-end, and put it in users’ hands.

You will fit right in if you have experience with:

• Product Engineering — Design and build end-to-end user workflows, from UI to backend logic and data

• User Experience — Translate complex real-world processes into clear, intuitive interfaces

• Frontend — Build production-grade UI using modern frontend frameworks (React, TypeScript)

• Backend — Implement APIs, business logic, and data models that support complex workflows

• AI Integration — Design and integrate AI-powered features (LLMs, agents, model-backed APIs) into user workflows

• Product Judgment — Be opinionated about what to build, what not to build, and when to ship

• Ownership — Build fast and ship production-grade systems with high ownership

WHAT YOU WILL DO

• Ship from Day 1 — Deploy to production immediately and own real product surface area

• Own it end-to-end — Create specs, figure things out, and build features end-to-end

• Solve real problems — From UX polish to backend logic to jumping on customer calls

WHAT WE ARE LOOKING FOR TECHNICALLY

• Strong experience with TypeScript and modern frontend frameworks (React or equivalent)

• Comfortable building backend services in Python

• Experience integrating AI systems (LLMs, agents, model-backed APIs) into production products

• Ability to reason about complex workflows, not just CRUD

Strong plus if you have:

• Founder or ex-founder experience

• Early-stage or stealth startup background

• Founder fellowships or similar environments (EF, YC, Antler, etc.)

• Experience building AI-powered products in production

• Experience working where requirements were unclear and evolving

YOUR FIRST MONTH

• Ship to production from day one

• Own problems end-to-end, from definition to deployment

• Do what needs doing, including UX polish, debugging, and customer interaction

WE OFFER

• Pace and purpose — In-person in London (visa sponsorship available)

• No friction — Relocation, visas, meals, and tools fully covered

• A tight-knit team — High standards, high trust, no politics