Founding Engineer

Founding Engineer - three early-stage London startups (AI)

About the roles

We're hiring product engineers for three venture-backed London startups. All are building AI products, all are early stage, and all want people in the office five days a week.

Two are Y Combinator. One is Entrepreneur First. One of the roles is a founding engineer position (you'd be the second engineering hire). The others are between seed and Series A.

Rather than listing three separate job descriptions, it's easier to apply once and we'll work out which of the three is the best fit based on your background and what you're looking for. If none of them land, we'll tell you straight.

Who this is for

People who plan to start a company themselves one day and want to learn what that actually looks like from the inside first. You're probably the kind of person who reads the changelog, has strong opinions about dev tools, and has shipped things outside of work that you didn't have to ship.

You should be comfortable across the stack, moving between Python and TypeScript without making a fuss. You don't need to have worked at a startup before, but you should understand what you're signing up for: small teams, high ownership, messy priorities, and real consequences when things break.

What you'll do

• Ship product end to end. Frontend, backend, infra when it matters.
• Work directly with founders on what to build and why.
• Own features from problem statement to production, often in the same week.
• Help shape engineering culture while it's still being written.

What we're looking for

• Strong engineering fundamentals, demonstrated either through work or side projects.
• Fluency in Python and JavaScript/TypeScript. Most of these teams use one or both heavily.
• Bias towards action. You'd rather ship something imperfect on Tuesday than something polished on Friday.
• Comfort with ambiguity. Early-stage work rarely comes with a clean spec.
• Based in London (or willing to relocate) and happy to be in the office five days a week.

What you get

• Meaningful equity in a company you can genuinely influence.
• Good salary, benchmarked against London startup market rates.
• The kind of technical autonomy that's hard to find once a company has a process team.
• Exposure to three of the most interesting founder networks in Europe (YC and EF).
• A clear view into how early-stage companies actually work, which is useful whether you end up staying, leaving, or starting your own thing.

How it works

Apply below. If your background looks like a fit, we'll have a short call to understand what you're looking for and which of the three companies makes the most sense. From there, you interview with the company directly.

Referrals

If you know someone who fits this better than you do, send them our way. £1,000 referral bounty if they land the role. No forms, just their name and a way to reach them.

Want it tightened, made longer, or adjusted in tone? Also happy to split it into three separate JDs if you'd rather have one per company, though I think the "apply once, we'll triage" framing probably converts better for this audience.