Software Engineer (Mid / Senior / Staff / Principal)

About Electric Twin Most organisations make their biggest decisions on a thin slice of evidence — a handful of customer calls, one survey, instinct when the data runs out. Electric Twin changes that. We're a behavioural simulation platform that lets organisations test ideas, messages, and decisions against synthetic populations — digital twins of real audiences — and get answers in minutes that would otherwise take weeks. The work is grounded, and the engineering is real. We've run over 40,000 evaluations across populations covering 155 countries. Independent academic research with Professor Michael Muthukrishna at the LSE found our outputs come back roughly 10,000× faster than traditional methods, at 95% accuracy. AI is part of what we build, but it isn't the product. The hard work is system design, data, orchestration, and making outputs trustworthy enough that people act on them. Running population-scale simulations is a systems problem as much as a science one — foundation models, behavioural data, evaluation pipelines, and the infrastructure that holds them together, with real engineering problems at every layer. How the work gets done here isn't handed down — it's worked out by the people closest to it. You'd help shape what gets built or sold and why, decide where the trade-offs sit between speed and depth, and judge when something is ready for customers and when it needs another pass. What the role involves day-to-day, what your first six months look like, and how compensation, equity, growth and flexible working are structured are all set out in detail below — the headline is that early joiners get meaningful equity, a clear path to grow with the company, and the flexibility to work around the rest of your life. Electric Twin was founded by Dr Ben Warner (former Chief Data Advisor to the UK Prime Minister) and our CEO, Alex Cooper (a former senior military commander and Director of Mass Covid Testing in the pandemic). We're backed by top tier investors including Atomico, LocalGlobe, Mercuri, and angels including Marc Andreessen. We have a high-class team of engineers, AI researchers, behavioural scientists, and operators — careful with the science, careful with the responsibility." The Work The work at Electric Twin is about turning complex decision-making into usable software. Engineers build the systems that let customers move from a broad question to a structured, trustworthy outcome — combining product experience, workflow logic, backend services, and platform capability into something coherent. Some of that work is highly customer-facing: shaping interfaces that make sophisticated workflows feel clear and accessible. Some is deeply systemic: designing the services, data models, APIs, and execution layers that make those workflows reliable and reusable. And some sits at the boundary between science and product, taking capabilities validated in research and turning them into robust product behaviour customers can depend on. The common thread is ownership of the whole problem, not just the implementation. Engineers here help shape the capability, decide what trade-offs are worth making between speed and rigour, judge when something is ready for customers and when it needs another pass, and stay with it as it evolves. Specs aren't handed down — they're worked out by the people building the thing. You'd be joining a delivery team of twelve: five engineers, five data scientists, and two designers, reporting to Rob Cherry, VP of Engineering. The shape of the team is deliberate — the science isn't a separate function that hands things over; it sits inside the team building the product. Our stack is Python, FastAPI, TypeScript, React/Next.js, PostgreSQL, GitHub, and Google Cloud Platform. Prior experience with these specific tools isn't required — we're happy to support your learning where you have less experience. Our most recent Principal Engineer hire came predominantly from a Java background, even though there's no sc