Senior Fullstack Engineer at CoLoop (S21) £90K - £120K GBP • 0.20% - 0.35% AI Copilot for insights & strategy London, UK Full-time US citizenship/visa not required 6+ years About CoLoop Consumer insights remain today one of the most important tools to truly understand behaviours that drive engagement with a brand, product or service. From leading businesses to political parties deep qualitative research is key to solving some of the most complex strategic challenges At CoLoop we are building the AI copilot for qualitative research, think heavily specialised ChatGPT that helps research and strategy consultancies produce decks and reports in 70% less time. About the role Skills: Node.js, Python, React, TypeScript, Amazon Web Services (AWS) Central London • hybrid remote Competitive Salary (+ EMI options) • full-time, permanent What is CoLoop? CoLoop: AI copilot for Insights & Strategy teams At CoLoop we’re on a mission to make every company in the world as customer obsessed as Amazon. We automate content analysis and knowledge management to provide a 70% time and cost reduction for market research. We’re used by 300+ large agencies & research teams globally including Amazon, Financial Times, P&G and Publicis Sapient. Profitable team of 11 based out of central London with $5M raised in total and growing fast — 400% ARR growth in the last 12 months. What we love to see in candidates You have built AI products for real customers in a team using typescript, python, the OpenAI, Claude, and / or Gemini APIs. You immerse yourself in startup culture, in and out of work. You read hackernews in your free time, and attend hackathons on the weekend. You work on side projects in your spare time when you’re bored at work. You have a favourite technical blog or youtuber. You relish solving hard problems — often through trial and error. You feel super comfortable making risky decisions. You hate working from home — unless you live in a hacker house. You want to be responsible for the success or failure of a feature. You believe you have good product ideas that are worth convincing others of. You can explain RAG both to a 5 year old and the CTO of a customer. You recognise that if you were truly working your hardest, it wouldn’t be 955. You also recognise that 996 is unsustainable. You recognise you have blind spots and want other people to point them out — and will happily return the favour. You write clean code if and only if it is in the best interest of the customer. You have an artisan's mindset toward your craft — you can explain what makes Linear great — both as a company and product. You want to get on call to fix a gnarly bug even though somebody else caused it. You understand the economics of tech debt, and when — or when not — to take out and pay off loans. Don't worry if all of these points don't describe you perfectly. If even a few of these points resonate with you, we'd still encourage you to apply! What you get You work directly with the founders and founding team on a daily basis — founders who pivoted away from a 7-figure business because the opportunity wasn’t big enough. You board a fast-paced ride and live through our scaling phase from a team of 11 to >25 in the coming 12 months. You join a tight knit team of 6 engineers — physics PhD, 18 y/o whiz kid, hackathon winner, and more. You build with cutting-edge generative AI, like our multi-agent system for qual content analysis. You are given true autonomy and time to research and implement the best solutions. Two engineers recently did a 2 week sprint entirely on GraphRAG. You are rewarded with above market comp + equity in a YC startup that’s at the very beginning of its revenue curve. You receive a generous workspace allowance and monthly expense account on anything you think will boost the business (our expense policy = do what's in CoLoop's best interest). You become part of a community of the best technologists in London. Adrien lives at the London Founder House. They regularly hosts dinners, hackathons and other events with top tech talent. You work on a seemingly unsexy — but in reality extremely valuable — problem space. Our customers include huge enterprises like Nike, Amazon, P&G, FT, and Kantar. About the job You’ll spend 90% of your time programming across the stack. The rest of your time is spent in code review and talking to customers. We operate on a two-week sprint cadence. We have two meetings: product, where we decide on what to build — and sprint meetings, where we decide on how to build. We have a 15 minute standup every day at 9am. We’re in our Oxford Circus office as often as possible (2 days min per week). Our stack Frontend React (Typescript) NextJS TRPC Backend NextJS TRPC Prisma ORM with Postgres Python for core AI service Infra Github Docker AWS CDK for CI/CD Qualifications You must have: 6+ years full-stack experience building web applications. 1+ years building generative AI applications. Ability to speak and write in English fluently. You have an edge over other candidates if you: Have been a founding engineer at a high growth company. Built an AI side project that makes more than $100 / month. Maintain an open source project on Github with traction. Have significant experience mentoring engineers. Were a qualitative researcher in a previous life. What our most recent hires are saying about us I wrote a whole blog post about my decision to quit my last job at a development agency and join a startup - it broadly covers why I think an enterprising engineer your best bet is to join a startup. Which start-up to join is a harder choice, but the result of my decision making process was joining CoLoop. The bottom line is that there’s a short list of fast growing <20 employee YC companies in London and CoLoop is at the top of the list. – Rohan Mahendraker, Founding Engineer Joining CoLoop has been the most energising move of my career. Every sprint has engineers working shoulder-to-shoulder with our commercial team, so the code you ship in the morning often sparks a client insight by the afternoon — you see your impact in real time. We experiment daily with the latest LLMs and a nimble stack that lets us ship fast, learn fast, and refine fast. If you thrive on close-knit collaboration, innovative tech, and work that matters the moment it goes live, CoLoop is the place to build. – Vlad Ursu, Senior Engineer How should you apply? If you think this is the right role for you and would like to reach out, please format your message as follows: 1-line introduction about yourself. 1-line with a URL to a live project or repository you built, or open source contribution you made highlighting the impact it has had. 1-2 lines explaining your interest in joining CoLoop. 1-2 lines outlining specifically how you believe you can contribute meaningful value to CoLoop. If relevant, mention any previous experience at a startup or within the market research industry. Feel free to include additional links to work or personal projects / any evidence of your work. If you're excited about this role but don’t meet every single requirement, we’d still love to hear from you. Studies show that women and underrepresented groups often hesitate to apply unless they check every box - we don’t want that to hold you back. So if this job sparks your interest, go for it! Interview Process Screening interview (30 min) Technical interview (45 min) Presentation of work sample (30 min) In-person, paid contract (1 day) Feedback Decision