Full Stack Engineer
Junior AI
<h2><strong>👶 About Junior</strong></h2><p style="min-height:1.5em">Junior is building the AI operating system for investment research. Our software helps private equity firms, consultants and financial institutions complete high-stakes research workflows dramatically faster - from diligence and memo writing to market mapping, research synthesis and strategic analysis.</p><p style="min-height:1.5em">We’re trusted by several of the world’s top private equity firms, Big Four consultancies and leading financial institutions.</p><ul style="min-height:1.5em"><li><p style="min-height:1.5em">Bootstrapped and profitable</p></li><li><p style="min-height:1.5em">~£20M+ in revenue, after growing 10x last year</p></li><li><p style="min-height:1.5em">60+ people across the company</p></li><li><p style="min-height:1.5em">20-person engineering team, doubling to 40 this year</p></li><li><p style="min-height:1.5em">Core stack: TypeScript, Next.js and PostgreSQL</p></li></ul><p style="min-height:1.5em">You’d be joining early enough to shape the product, engineering culture and company, but with enough traction that everything you build lands immediately in front of demanding, paying customers.</p><div style="min-height:1.2em;margin-top:0;margin-bottom:0"> </div><h2><strong>💡 The role</strong></h2><p style="min-height:1.5em">You’ll own features end to end - across the frontend, backend and data layer - and ship on a weekly cadence, not a quarterly one.</p><p style="min-height:1.5em">You’ll:</p><ul style="min-height:1.5em"><li><p style="min-height:1.5em">Ship quickly, then ship again</p></li><li><p style="min-height:1.5em">Design and build entirely new ways of working with computers</p></li><li><p style="min-height:1.5em">Work on groundbreaking projects involving LLMs</p></li><li><p style="min-height:1.5em">Speak directly with the clients using what you build</p></li><li><p style="min-height:1.5em">Use those conversations to shape product decisions</p></li><li><p style="min-height:1.5em">Help define Junior’s engineering culture as the team doubles</p></li></ul><div style="min-height:1.2em;margin-top:0;margin-bottom:0"> </div><h2><strong>🔧 Sample projects</strong></h2><ul style="min-height:1.5em"><li><p style="min-height:1.5em">Build frontier products capable of ingesting new types of research inputs</p></li><li><p style="min-height:1.5em">Build an extremely low-latency, voice-to-voice survey tool that autonomously conducts high volumes of research</p></li><li><p style="min-height:1.5em">Build a mobile app from scratch in three weeks</p></li><li><p style="min-height:1.5em">Create segmented knowledge graphs using unstructured-to-structured data transformations</p></li><li><p style="min-height:1.5em">Build an AI-native CRM with deep links into that knowledge graph</p></li></ul><div style="min-height:1.2em;margin-top:0;margin-bottom:0"> </div><h2><strong>🔥 About you</strong></h2><ul style="min-height:1.5em"><li><p style="min-height:1.5em">You have 3+ years of engineering experience - we care about demonstrated competence, not pedigree</p></li><li><p style="min-height:1.5em">You’re genuinely strong in TypeScript, Next.js and PostgreSQL, not merely familiar with them</p></li><li><p style="min-height:1.5em">You can build a polished React/Next.js interface or work through a difficult TypeScript problem live and quickly, without relying on Copilot</p></li><li><p style="min-height:1.5em">You have solid foundations in data structures, system design and PostgreSQL</p></li><li><p style="min-height:1.5em">You’re high-agency and product-minded</p></li><li><p style="min-height:1.5em">You’ve owned projects end to end, argued for what should be built - not only how - and shipped without being handed a detailed specification</p></li><li><p style="min-height:1.5em">You communicate clearly and want a client-facing role</p></li><li><p style="min-height:1.5em">You’re based in London, or already committed to relocating, and excited to work with the team in person in Farringdon</p></li><li><p style="min-height:1.5em">You feel like you’re never building fast enough</p></li><li><p style="min-height:1.5em"><u>Bonus</u>: you’ve built and designed AI-powered products</p></li></ul><div style="min-height:1.2em;margin-top:0;margin-bottom:0"> </div><h2><strong>🧭 Interview process</strong></h2><p style="min-height:1.5em">The process moves in days, not months:</p><ol style="min-height:1.5em"><li><p style="min-height:1.5em"><strong>Introductory call</strong>: background, motivation and mutual fit</p></li><li><p style="min-height:1.5em"><strong>Live technical screen (30-mins</strong>): solving a TypeScript problem live in an IDE with one of our engineers. We optimize for speed and completeness over polish, and the interview is completed without AI tools</p></li><li><p style="min-height:1.5em"><strong>On-site Interview</strong>: a full afternoon of coding, a system-design whiteboard and a product discussion with one of our PMs</p></li><li><p style="min-height:1.5em"><strong>Final Cultural Round</strong>: a final conversation about how you work, what motivates you and whether Junior is the right environment for you</p></li><li><p style="min-height:1.5em"><strong>Offer</strong>: decisions are made collectively and quickly</p></li></ol><div style="min-height:1.2em;margin-top:0;margin-bottom:0"> </div><h2>🌵 Benefits</h2><ul style="min-height:1.5em"><li><p style="min-height:1.5em">Private health insurance</p></li><li><p style="min-height:1.5em">Third Space gym membership</p></li><li><p style="min-height:1.5em">Dinner provided when working late</p></li><li><p style="min-height:1.5em">Team lunch provided every day at the office</p></li><li><p style="min-height:1.5em">Frequent international off-sites, recently including Crete and Cancún</p></li></ul><p style="min-height:1.5em">If you’re excited to drive innovation at Junior, we’d love to hear from you!</p><hr><p>Compensation: £90K – £110K • Offers Equity</p><ul><li>Junior/Mid • Estimated Base Salary £90K – £110K • Offers Equity</li></ul><p>Find <a href="https://www.arbeitnow.co.uk">Jobs in United Kingdom</a> on Arbeitnow</a>