Founding Applied AI Engineer (£100k-£120k + Equity) at Stackfix

This is a job that Jill, our AI Recruiter, is recruiting for on behalf of one of our customers. She will pick the best candidates from Jack's network. The next step is to speak to Jack. Job Title Founding Applied AI Engineer Salary £100k-£120k + Equity Company Description Stackfix is a Tier 1-backed London startup founded by repeat entrepreneurs who sold companies to TikTok and the HR sector. We deploy frontier AI inside real-world businesses—from PE funds to manufacturers—building production systems that handle real transactions and drive tangible profits through technology diffusion and custom workflow automation. Job Description You will join Stackfix as a founding engineer to build and deploy production AI systems for diverse industries. Working directly with exited founders, you’ll bridge the gap between frontier models and enterprise workflows, shipping end-to-end software that processes real transactions. This is a high-agency role focused on solving valuable, real-world problems. Location London, UK Why this role is remarkable * Work directly with repeat founders Paddy Stobbs (sold Jukedeck to TikTok) and Tom Dekan, gaining unique daily insights into selling, building, and scaling AI. * Gain unparalleled exposure to frontier AI in production, learning which models and methodologies actually deliver value in high-stakes business environments rather than just following hype. * Enjoy rapid variety by solving unique problems across diverse sectors like PE funds and logistics, providing better entrepreneurial preparation than years spent on a single product. What You Will Do * Build and ship production-ready AI systems end-to-end, from initial scoping with enterprise clients to deploying software that handles hundreds of daily transactions. * Join client calls and visit sites to understand complex business workflows, presenting your work directly to leadership at global firms and investment funds. * Iterate on frontier AI models and tooling to create robust systems that review patient records, process factory orders, or audit complex financial obligations. The ideal candidate * Possesses 4+ years of full-stack software engineering experience with a proven track record of shipping production systems rather than just building isolated features. * Demonstrates high agency through a portfolio of side projects or open-source contributions that show a natural hunger for building and solving technical problems. * Combines strong technical implementation skills with a genuine curiosity about business operations, capable of learning fast and performing at a high level in person. Who are Jack \& Jill? Ok, I'll go first. I'm Jack, an AI that gets to know you on a quick call, learning what you're great at and what you want from your career. Then I help you land your dream job by finding unmissable opportunities as they come up, supporting you with applications, interview prep, and moral support. And I'm Jill, an AI Recruiter who talks to companies to understand who they're looking to hire. Then I recruit from Jack's network, making an introduction when I spot an excellent candidate. How does this work? * Jack's an AI agent for job searching and career coaching. He works for you. * Jill is the AI recruiter working for the company. She recruits from Jack's network. * If it's a match and the company wants to meet you, they'll make the intro. In the meantime, if you'd like, Jack will send you excellent alternatives. We never post fake jobs This isn't a trick. This is an open role that Jill is currently recruiting for from Jack's network. Sometimes Jill's clients ask her to anonymize their jobs when she advertises them, which means she can't share all the details in the job description. We appreciate this can make them look a bit suspect, but there isn't much we can do about it. Give Jack a spin! You could land this role. If not, most people find him incredibly helpful with their job search, and we're giving his services away for free.