Ex Technical Founder in London

We started CoLoop in 2020 while still at university. We survived multiple cofounder breakups and all sorts of other near-death experiences. Despite that, we built our first product to $1M ARR and then killed it after realising the opportunity was too small and we didn’t have real PMF. We spent six months pivoting, and through that process came to understand just how important customer research is to finding a winning strategy. So we built a product to make it faster, cheaper, and better.

We don’t tell you this because we think suffering is something to aspire to. We tell you because if you’re an ex-founder evaluating whether to work for someone else, you should know who you’d be working with. We are not going to sell early, get comfortable, or lose interest. This is everything to us.

We also take seriously that you’re trusting us with your time. Three people who’ve worked at CoLoop have gone on to become YC founders. When you’re here, we’ll share everything we know and everything we learn along the way. All we ask is total commitment. And if you eventually get the itch to build your own thing again, we will back you 100%.

We’re looking for ex-founders who want to write code, ship product, and work on hard problems in agentic AI. At CoLoop, engineers own the full cycle. There are no product managers. You gather context, decide what to build, build it, launch it, measure the impact, and iterate. We track individual attribution in PostHog. One engineer recently drove 40 new active users through a single small growth experiment.

The structure is flat. Influence is earned through skill and context. We’d rather you make a wrong call than wait to be told what to do. We think ex-founders tend to work well here because the expectations match how they already think: own the problem, move quickly, care about customers, and measure what matters. If you’ve built and run a company before, the pace and autonomy at CoLoop will feel familiar.

If you failed to find PMF, we’re building the product that helps companies avoid that fate. Your experience is valued here.

What we’re looking for:

• You’ve founded or co-founded an AI startup.
• You’ve built and shipped product yourself.
• You’ve shipped complex agent systems to production.
• You have strong opinions about AI-augmented engineering. We use Claude Code, Codex, Conductor, Greptile, and more. We want someone who’s always finding the next thing that makes the team faster.
• We know a lot about multi-agent systems and context engineering. We want to learn something we haven’t thought about yet.
• You know when to cut corners and when to be rigorous. Move fast at the edges, build carefully at the core.
• You can explain what an AI agent is to both a 5-year-old and the CTO of a customer.
• You recognise you have blind spots and want other people to point them out, and will happily return the favour.
• Bonus: you’ve led an engineering team of 3+ people; you have experience with enterprise customers.

How to apply:

• 1-line on your background.
• 1-2 lines on what you built and what you took away from it.
• A URL to a live project, repository, or open source contribution you made.
• 1-2 lines on your interest in CoLoop and how you’d contribute.

Interview process (~1-2 weeks):

• Screening interview (30 min)
• Technical interview (45 min)
• Presentation of work sample (30 min)
• In-person, paid contract (1 day)
• Decision

If you’re excited about this role but don’t meet every requirement, we’d still love to hear from you. If you’d like to meet the team, we host CoLoop CoWorking from our office most Saturdays.