Founding Engineer – Mobile & AI (Stealth Start-up | Launching 2026)

ECW Search; Remote; GBP 100,000 - 125,000; Full time

Job summary

A stealth start-up is seeking a Founding Engineer in Mobile & AI to develop a category-defining AI product. This remote role involves building the mobile app from scratch, integrating advanced technologies, and shaping the product vision. Ideal candidates have strong experience in mobile engineering and a passion for building intuitive, high-performance applications. This is an exciting opportunity to influence the identity of a pioneering AI platform launching in 2026.

Benefits

Competitive compensation

Meaningful equity

Qualifications

• 4+ years professional engineering experience.
• Experience shipping and maintaining mobile apps.
• Strong ability to take product requirements and turn them into elegant software.
• Clear understanding of building scalable backend systems.
• Prior experience in a start-up or small team strongly preferred.

Responsibilities

• Build the mobile app from scratch.
• Implement a delightful, world-class user experience.
• Integrate with leading LLM APIs.
• Help shape the product roadmap & feature prioritization.

Skills

React Native

Node.js

Python

PostgreSQL

Firebase

Job description

Founding Engineer – Mobile & AI (Stealth Start-up | Launching 2026)

Location : Remote

Type : Full-Time / Founding Team

Salary : Competitive compensation (salary + meaningful equity)

Start Date : Jan 2026

About the Company

Our client is a stealth start-up launching publicly in 2026, building an AI-powered personal transformation platform designed to change how millions of people grow, learn, and express themselves.

The next decade will be defined by AI-powered personal development, and our client is building a flagship product that helps people unlock opportunities, find confidence, and improve their lives through intelligent, real-time guidance.

The business is backed by experienced operators and builders, and they’re assembling a world-class founding team to bring this vision to life.

Founding Mobile & AI Engineer

We’re searching for a founding full-stack / mobile engineer who wants to build a category-defining AI product from the ground up.

You will be responsible for taking the product vision and turning it into a beautifully polished, high-performance mobile experience used by people around the world.

What you will own

• Build the mobile app from scratch
• Implement a delightful, world-class user experience centred on :
• Real-time voice interaction
• AI-powered feedback and insights
• Daily habit-building loops
• Smooth animations and micro-interactions
• Build and maintain a scalable backend (Node / Python).
• Integrate with leading LLM APIs (OpenAI / Anthropic / etc.).
• The early architecture, tech stack, and development culture.
• Ship fast, iterate fast, and help create something users genuinely love.

What you will help shape

• Product roadmap & feature prioritisation
• Engineering practices & development velocity
• Infrastructure & data systems
• Future hiring for engineering and design

This is a rare opportunity to be the person who actually builds the first version of a company’s flagship AI product.

The Person

First and foremost, you will be a builder at heart. You love creating new things, shipping 0→1 products, and turning ideas into polished experiences. You’re happiest when you’re building.

A mobile engineer with taste who cares about clean UI, smooth motion, intuitive interactions, speed and craftsmanship.

You don’t need to be an expert in everything, but you should be confident working with :

• React Native or Swift / SwiftUI
• Node.js / Python backend
• PostgreSQL / Firebase
• API integrations
• Authentication & subscriptions

Experience Required

• 4+ years professional engineering experience.
• Experience shipping and maintaining mobile apps.
• Strong ability to take product requirements and turn them into elegant software.
• Clear understanding of building scalable backend systems.
• Prior experience in a start-up or small team strongly preferred.

If you’re inspired by the idea of building and taking a new AI product into the real world, shaping its identity, and leading the journey to launch, we would love to hear from you.