Full Stack Developer

Hello, we’re Honest. 👋 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 🚀

Role overview 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.

Key responsibilities Design, build, and maintain scalable backend services and APIs using TypeScript and Python. Develop performant, intuitive frontend features for internal and customer-facing tools. Work with Postgres to design efficient schemas and write clean, optimized SQL. Contribute to infrastructure and DevOps – from CI/CD pipelines to monitoring and alerting. Help setup 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.

About you You're a strong generalist with experience across both frontend and backend. You’re fluent in modern TypeScript but you’re language-agnostic and enjoy quickly learning new languages and technologies. You’re comfortable with infrastructure, DevOps, networking and cloud deployment (bonus: GCP experience). You’re skilled with relational databases (Postgres) and writing efficient SQL, and ideally have worked with NoSQL 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 are happy asking questions or challenging assumptions. You’re excited by AI and its potential to accelerate development and assist with fast iteration and experimentation.

What you’ll get in return for all your hard work? Salary: £70,000 - £80,000. Ownership in Honest through our EMI option scheme. 25 days of annual leave, plus all bank holidays. Your birthday off each year on us! A hybrid-first working environment with at least 1 day per week in the London office. An Honest sim, and refurb phone on us. 1 paid volunteering day each year. Wellbeing budget through Heka. Cycle to Work scheme. £500 annual learning budget. Regular in-person team socials. Private medical insurance.