Sema-who? Semaloop.

From humble beginnings with a small device farm in Charlie's shed, we saw first-hand how agentic coding unlocked many barriers to building apps, but ensuring that they run reliably was still incredibly painful. Whether at early-stage startups or tech-giants, flaky tests blocked releases and were the real bottleneck in getting new features into customers' hands.

We're on a mission to change that by building agents that test apps like humans do: through sight, sound and touch. We believe developers shouldn't need to maintain special APIs, accessibility IDs or integrate new libraries, but rather whenever a new build is shipped all of the important workflows are verified before reaching users, automatically, by an agent. If there's a bug, those developers shouldn't need to talk about flaky tests, but rather see that their coding agent has already received the full context in order to fix exactly what's broken. That means an end to manual testing, and hours of time back per day for developers.

Our vision is to build the go-to operating layer for mobile that not only cuts across code verification and testing, but also all other friction points in the mobile journey: writing the app, shipping it, monitoring performance, learning from users, growing revenue, and ensuring everything is secure. We think we're best placed to do this with our agentic multimodal approach.

This effort spans ML, real physical hardware, and software development. If you're excited by the idea of teaching computers to understand, reason and interact with digital interfaces, you belong on this mission with us. We're assembling a small all-star team here in London, with the ambition to truly change how mobile software is made.

We think that's part of what makes it exciting, but it should also be a conscious choice. So rather than trying to oversell it, this is a straightforward look at how we think about things, how we work, and what it actually feels like to be here.

Our approach to compensation

We're currently offering what we think is highly competitive compensation. Specifically, that's somewhere around the 80th percentile for London on cash, and 95th percentile on equity.

Joining an early-stage company always comes with some level of risk, but we don't want our early team to have to compromise on everything, so that's why we pay as we do. The idea being that if we all do well as a team, we all have a share in that success.

What we're like (and how to find out)

We could try and pitch ourselves as uniquely different to other startups… but the reality is we'll probably sound quite similar. Low ego, high trust, lots of autonomy, no rigid hierarchy, bias to action, supportive, honest, flexible… you've heard it all before.

We genuinely do think we're true to those things, but we'd love for you to come and see it for yourself. That could mean swinging by our Old Street office for a coffee, spending a day working from one of our free desks, or as part of the interview process as a paid half or full 'Semaloop Day' depending on your preference.

Ultimately, we want you to get a proper feel for who we are, how we work, and what a normal day actually looks like. You can read for yourself what Sam's first week looked like.

How we work

When it comes to work-life balance, we're a team that works hard and wants to achieve something meaningful, but we value balance. Part of that is how we handle it when things start to feel off. We try to be good at talking about it, by calling it out early and adjusting when possible.

Most days are pretty normal. There are times we'll push harder when something exciting is happening. Then there will be the occasional crunch period, with all hands on deck. But it's not constant, and we don't want it to be.

We value time in person and want to keep that for now — we have a lovely office in Old Street. That said, we're flexible. We understand people have lives, errands to run, things to do at home, or maybe a day full of calls (we don't expect you to come in just to live in a phone booth).

Who tends to thrive here

People we think will do well here are lifelong learners, back themselves to figure things out, and have a core specialism but are happy operating as a bit of a generalist.

It also helps if you're not afraid to dive into unfamiliar territory head first, get your hands dirty, and learn as you go. A lot of what we do involves figuring things out in real time rather than following a set playbook.

This kind of environment is especially exciting for people who have founded, or want to start, a company one day, and so are looking for broader exposure beyond a typical role. In addition, people who want to be involved in wider business decisions, contribute to shaping direction, and explore new domains, ideas and problems.

Ultimately, we're trying to create a space where people can learn quickly, take on real responsibility, and do so in a supportive, low-ego environment where you're trusted to get on with things.