Full Stack Developer

❄️ We’re currently on a winter break, and enjoying one too many mince pies. If you’re applying now, we’ll be in touch in January. We can’t wait to read your application.

The clue’s in the name: we’re the network doing mobile right.

We’re on a mission to set a bold new standard for mobile (and drag a broken industry into the future while we’re at it).

It started with Classic SIM, our essential everyday SIM that includes bills that drop, support in seconds, and a shrinking carbon footprint.

Thousands of happy customers joined us. But we knew people still faced two big problems: rubbish signal and expensive roaming.

So we built Smart SIM, our game‑changing back‑up eSIM giving you unbeatable signal and free global roaming. Whenever you lose signal or go abroad, you can switch to Smart SIM in just a few taps for 500+ essential apps on EE, O2, Three and Vodafone, plus hundreds of networks worldwide.

Now we’re proud to have more than 63,000 customers on our journey.

We’re also the UK’s first B Corp mobile network, a carbon‑negative company and member of 1% for the Planet.

But building the world’s best mobile network requires having the right people to help us do it. That’s where you could come in.

Like the sound of honest? Read on. This could be the start of something exciting.

We’re looking for a talented and curious Full Stack Developer to help take our product to the next level.

Our engineering and product teams are already disrupting the industry with our unique, 4‑network, data‑only product,
Smart SIM
. But we know there’s much more to build. That’s where you come in.

In this role, you’ll help shape the technical direction of our product, looking beyond the standard stack to introduce new technologies, techniques, and ideas. You’ll play a key role in the full development lifecycle, delivering high‑quality features and continuously improving how our backend and frontend platforms are built.

You’ll work across our API, databases, network and infrastructure, internal tools (including team and customer‑facing dashboards) and web‑based interfaces, creating experiences that truly delight our users.

Reporting to the Head of Engineering, you’ll be a core part of our small but mighty tech team, collaborating closely with developers and product to make a meaningful impact across the full stack.

Our engineering team is at an exciting stage of growth as we explore how AI can accelerate development, level up our coding, enable fast adoption of new languages and frameworks, to help us achieve our ambitious goals.

• Design, build, and maintain scalable backend services and APIs using Type Script and Python
• Develop performant, intuitive frontend features for internal and customer‑facing tools
• Work with Postgres to design efficient schemas and write clean, optimised SQL
• Contribute to infrastructure and Dev Ops – from CI/CD pipelines to monitoring and alerting
• Help set up and maintain networking and firewall rules with tools like iptables, tc, Suricata, RADIUS
• Deploy and manage services on Google Cloud Platform, using its managed tools and infrastructure
• Collaborate in code reviews and architecture discussions to maintain high engineering standards
• Troubleshoot and resolve production issues across the full stack
• Work cross‑functionally with product, customer operations, and marketing to deliver seamless user experiences
• Help shape engineering best practices and build internal tools to support our team
• You’re a strong generalist with experience across both frontend and backend
• You’re fluent in modern Type Script but you’re language‑agnostic and enjoy quickly learning new languages and technologies
• You’re comfortable with infrastructure, Dev Ops, networking and cloud deployment (bonus: GCP experience)
• You’re skilled with relational databases (Postgres) and writing efficient SQL, and ideally have worked with No
  
  SQL and other database types too
• You’re pragmatic, curious, and motivated by solving real user problems
• You’re comfortable owning projects end‑to‑end in fast‑moving environments
• You’re committed to clean, maintainable and well‑documented code
• You’re a clear communicator, who collaborates well and isn’t afraid to challenge assumptions and is…