Senior Product Growth Engineer

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 Senior Product Growth Engineer Salary £65k-£80k + Equity Company Description readywhen.ai is a London-based pre-seed AI startup building the first "senior AI employee" for small-business owners. The platform connects to existing business tools to automatically draft client updates, proposals, and reports based on real-time context, eliminating the need for manual prompting or complex setup for busy founders. Job Description Join readywhen.ai as our first dedicated growth hire to own the product loop from code to conclusion. You will bridge the gap between engineering and GTM, building fast-paced experiments, instrumenting the activation funnel, and driving retention. This is a high-autonomy, full-stack role for a senior engineer who thinks like a founder. Location London, UK Why this role is remarkable Join a high-velocity, pre-seed team as the first growth hire, directly influencing the product's trajectory and core business metrics from day one.Work at the cutting edge of AI-assisted development, utilizing tools like Claude Code and Cursor to accelerate shipping while building a truly autonomous AI product.Enjoy complete ownership over the growth stack, from building experiment scaffolding to performing statistical analysis, without the friction of traditional PM specifications. What You Will Do Optimize the end-to-end activation funnel by identifying user drop-off points and shipping rapid, data-driven fixes to improve onboarding momentum.Design and build a robust experimentation framework using tools like GrowthBook or PostHog to run scientifically-driven A/B tests behind feature flags.Own the company's data integrity by designing Amplitude event taxonomies and building automated lifecycle messaging flows to drive long-term user retention. The ideal candidate Brings senior-level experience shipping growth features at B2B or prosumer startups, with a proven track record of moving activation and retention metrics.Expert in TypeScript, React, and SQL, with the ability to query your own data and write clean, reviewable production code.Exhibits a founder mindset, capable of identifying high-impact bets independently while maintaining enough architectural respect to know when a fix belongs in an experiment. 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.