Senior Software Engineer – Node.js / AWS / React – London (Hybrid, 3 days onsite) Are you the kind of engineer who enjoys taking something fast-and-scrappy and turning it into something scalable, elegant, and genuinely robust? This is a chance to join a small, but ambitious tech-for-good / IoT startup based in the London City Centre that’s building products to make sense of massive data streams. You’ll be part of a tight-knit team (around ten people total, five engineers), working on a genuinely greenfield platform with a modern stack and zero legacy The focus now is on maturing the codebase – re-architecting, refactoring, testing, and scaling. You’ll play a key role in helping the team evolve from early-stage speed to long-term stability, with the freedom to influence both product direction and engineering quality What you’ll be doing: * Building and scaling a Node.js application that sits at the core of the product * Designing and implementing new features for different sectors and use cases * Helping drive improvements in code quality, architecture, and testing practices * Working closely with product and engineering to prioritise, shape, and deliver features * Introducing best practices and guiding a shift towards cleaner, more maintainable code What we’re looking for: * Strong hands-on experience with Node.js * Comfortable working across or picking up other tech as needed – ie AWS, React etc (If you have experience with AWS & React, that is a bonus) * Enthusiasm for writing clean, tested, production-ready code * Experience (or interest) in data-heavy systems, IoT, or connected devices If you’re an engineer who likes solving real problems, shaping a product, and being part of something early, please apply and have a further conversation