Software Engineer (Mid / Senior / Staff / Principal)

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 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 scope to use Java in the role.

We don't have a fixed checklist of years, frameworks, or job titles. The work is what matters, and the people who do it well tend to share three things.

They take ownership of problems, not just tasks. The work here often starts ambiguous — a customer need that isn't fully formed, a capability that needs shaping into a product, a trade-off no one has made yet. We're looking for engineers who see that as the interesting part, rather than something to be resolved by someone else before they begin.

They have good judgement under uncertainty. Most of the decisions that matter are trade-offs: speed vs rigour, scope vs polish, building now vs validating further. We're less interested in whether you reach exactly the same answer we would, and more in whether you can reason about the trade-off clearly and explain why you landed where you did.

They ship and learn. Thinking carefully about a problem is necessary but not sufficient. The engineers who thrive here are the ones who get things in front of customers, learn from what happens, and iterate — rather than waiting for the design to be perfect before anything moves.

A note on experience. We've hired engineers across a wide range of experience levels and stacks, and the pattern is clearer than we expected: years matter less than what you've actually owned. People thrive here at every stage — what they share is a track record of having taken real responsibility for real problems, whether that came after two years or twenty. The ones who tend to struggle are those who've mostly worked inside tightly defined roles where the hard decisions were made elsewhere — not because they aren't capable, but because the work demands a kind of ownership that usually has to be learned by doing it.

If you've owned something meaningful end to end — shaped it, made the trade-offs, shipped it, and lived with what happened next — we'd like to hear from you, regardless of how long that took.

Small team, experienced and low-ego, with fast feedback and few layers. People care about getting to the right answer rather than being right — founders included. Disagreement is welcome and decisions are explained.

We're based in Soho, central London and have a strong in-office culture. Collaboration here is real, not ceremonial — the work genuinely improves when people are in the room.

Plenty of companies will tell you they value work-life balance while filling your calendar with 7pm "optional" meetings and stocking the kitchen so you never leave. We're not that. People here have kids, partners, dentist appointments, school plays, and the occasional delivery that somehow needs a signature in the middle of the day. The expectation is simple: do excellent work, and have an actual life alongside it.

• Equity. All full-time employees are enrolled in our share options scheme at the end of probation — explained in detail when you join.

• Pension. We match your individual contributions up to 8% (16% total) under a net pay structure.

• Private healthcare with BUPA.

• Unlimited leave — and we genuinely expect you to take it.

• £1,000 annual L&D budget to spend as you see fit.

• Cycle to Work Scheme.

• Kit. Laptop plus any accessories you need (monitor, keyboard, etc.) to do your best work.