Join a high-intensity team of 12 engineers that scaled from $1M to $30M ARR in just one year. As a Lead Product Engineer, you will own entire product areas without PM interference, building sophisticated AI-generated email systems that currently automate 53% of user drafts for a global professional audience.
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London, UK£140K – £250K + Equity
Featured roleLondon, UK£140K – £250K + Equity
Lead Product Engineer at Fyxer AI — Hyper-growth Applied AI Startup
Join the breakout AI startup ranked #7 on Andreessen Horowitz’s top AI apps list. Fyxer AI is solving the world's email problem and has exploded from $1M to $30M ARR in a single year with a lean team of just 12 engineers. We are looking for a Lead Product Engineer to take complete ownership of product strategy and execution—no PMs, no bureaucracy, just elite building. With a package up to £500k and the chance to shape a future $10B company, this is the ultimate role for a founder-level engineer ready to ship at light speed.
Overview
Why this role stands out
Company
Software
Fyxer AI - Series A pure-play applied AI company backed by Marc Benioff, Madrona, and Lakestar.
Responsibilities
What you will do
- Lead the end-to-end development of core AI features using TypeScript, fine-tuned open-source models, and RAG architectures.
- Drive product strategy by translating ambiguous user problems into high-impact technical solutions without needing external specifications.
- Build and optimize scalable infrastructure to support rapid user growth while maintaining elite engineering standards and craft.
Candidate profile
Who this is a fit for
- 5+ years of experience shipping production software with deep expertise in TypeScript or Python and end-to-end system ownership.
- Proven track record of building and deploying modern AI/ML solutions, including LLMs, embeddings, and inference optimization.
- Founder-level mindset with a bias for action, comfortable operating with extreme autonomy in a fast-paced, high-stakes environment.
What makes it remarkable
Why this role is remarkable
- Ranked 7th in Andreessen Horowitz’s list of top AI apps based on real spend data, alongside $10B+ companies.
- Extraordinary growth trajectory from $1M to $30M ARR in 2025, with a clear path to $100M ARR by 2026.
- Massive ownership with zero bureaucracy, no product managers, and company-wide deep-work focus time until 3pm daily.
Jack & Jill
How Jack & Jill work together
I get to know what you’re great at, then find roles you’d never find yourself.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.
I recruit from Jack’s network and make the intro when I spot a great match.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.
About Jack & Jill
Meet Jack
Jack gets to know what you are great at, what you want next, and makes sure Jill considers you for the right opportunities.
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.
Jack