Full-Stack Engineer (Frontend)

United States Digital Space LLC; Greater London; On-site; GBP 90,000 - 135,000; Full time

Benefits offered by this job

Direct access to founders

Competitive salary

25 days' annual leave

Central London office

Team offsites

Cycle-to-work scheme

Job summary

The London-based startup is seeking a full-stack engineer with a frontend focus to design and build web experiences that help brands and retailers engage shoppers. You will own features end-to-end, from concept through production, collaborating with product, design, and ML teams.

You will work with TypeScript, React, and real-time data patterns (WebSockets/SSE), deploying to AWS and contributing to API and system design. This role is office-based in London and offers equity and strong benefits.

Qualifications

• Frontend depth with production web applications owned end-to-end.
• Strong UX sensibility and web design fundamentals.
• Experience with real-time or bi-directional communication protocols.
• Comfort going down the stack and contributing to API/system design.
• Built and deployed services on major cloud providers.
• You care about users and shipping value fast.

Responsibilities

• Full-stack delivery end-to-end from product concept to production.
• Design and build reactive, real-time interfaces for brands and retailers.
• Translate user and business needs into simple, elegant UI.
• Collaborate with cross-functional teams on prototyping and shipping.
• Contribute to API design, system design, and docs.
• Own testing, observability, and post-release investigations.

Skills

Frontend

UX design

Real-time

Full-stack

Cloud

Product mindset

Shipping fast

AI-native

Tools

Python

FastAPI

PostgreSQL

Kafka

MQTT

Job description

About Us

At the company, we are reinventing one of the world's most familiar experiences: the in-store grocery trip. We are building an AI-native product that understands each shopper, responds to their context in real time, and makes an everyday experience less stressful, more personal, and more engaging.

We're backed by leading investors and founded by two entrepreneurs: one with a track record of building companies, and the other a leader in retail data and shopper analytics. Together, they have brought together frontier AI researchers and engineers, product and strategy leaders, and senior operators from major UK and US grocery businesses.

The people who join now will have an opportunity to shape the product, the engineering culture, and what the company becomes.

The Role

This role reports to our Head of B2B Product, James. Working with him and our product, design, mobile, and machine-learning teams, you'll design and build the web experiences that redefine how brands and retailers serve their shoppers.

You'll be a full-stack engineer with a frontend centre of gravity, going as far down the stack as each feature needs. You'll turn ambitious and sometimes ambiguous product ideas into software that retailers and brand partners rely on to create, launch, and measure their in-store activity.

You'll be shaping the interfaces that our B2B customers use every day, making the calls on how complex, intelligent capabilities get expressed through interfaces that non-technical users can pick up and trust.

We're agentic‑first. Every engineer has access to frontier AI tooling and our own coding harness, and we expect you to use them to move faster, attempt more ambitious work, and stay fully accountable for what you ship.

What You'll Own

• Full-stack delivery end-to-end. Own substantial features from product conversation through design, implementation, and iteration in production. Most of the weight sits in the frontend, but you go as far down the stack as the feature needs.

• Reactive web interfaces. Design and build the responsive, real-time interfaces that let brands and retailers manage and analyse the in-store experience our product delivers.

• Translating complexity into simplicity. Turn user and business needs into interfaces that make complex, intelligent capabilities feel elegantly simple to non-technical audiences.

• Product partnership. Work in a cross-functional team alongside our Head of B2B Product, prototyping and validating ideas quickly, then shipping the ones that hold up.

• API and system contribution. Contribute to API design, system design, and documentation as part of end-to-end delivery, not as an afterthought.

• Production quality. Own testing, observability, and post-release investigation for the interfaces you ship.

About You

Must Have

• Frontend depth. Expert proficiency in TypeScript and React, with a portfolio of production web applications you've owned end-to-end.

• UX and design sensibility. Strong understanding of UX principles and web design fundamentals. You care about interfaces that feel considered, not merely functional.

• Real-time and reactive patterns. Experience with real-time and bi-directional communication protocols (WebSockets, SSE) and managing complex asynchronous state.

• Full-stack capability. Comfortable going down the stack when features call for it, and confident contributing to API and system design conversations.

• Cloud deployment. You've built and deployed services on at least one major cloud provider (AWS, GCP, or Azure).

• Product mindset. You care about the people using what you build, and you take ownership for what your team puts in front of them, not just the part you wrote.

• Shipping at pace. Evidence that you can move complex, customer-facing products into production quickly, making pragmatic decisions without letting perfection become a blocker.

• AI-native engineering. You've shipped production code with frontier AI tools (Cursor, Claude Code, or similar) and push further into agentic workflows rather than push back on them.

Nice to Have (or We Can Teach)

• Backend and event-driven experience. Comfort with backend development and event-driven architecture. Our stack includes Python, FastAPI, Postgres, Kafka, and MQTT.

• IoT or edge architectures. Experience working with IoT, edge computing, or hardware‑adjacent systems.

• B2B or enterprise product experience. Background building for business or enterprise customers, where reliability, integrations, and data pipelines matter as much as the interface.

• Retail or personalisation. Familiarity with retail technology, commerce platforms, inventory systems, loyalty programs, or customer personalisation.

• Startup experience. Background working at an early‑stage startup.

How We Work

We're a startup, so this is a high‑intensity environment. The people who thrive here are curious, proactive, and love building. If you're happiest when you're creating, experimenting, and moving fast, you'll love it here.

We draw our energy from being together, so this is an office‑based role. It suits someone who enjoys the quick conversations and shared momentum that comes from building together. Our office is on what we think is the best garden square in London, just a couple of minutes from Tottenham Court Road, so it's easy to get to and a great place to build.

What We Offer

• Direct access to our founders and a real voice in decisions that shape the product and company.

• Competitive salary and meaningful equity.

• 25 days' annual leave, plus bank holidays.

• A central London office.

• Team offsites.

• Cycle-to-work scheme.