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.
Lead Product Engineer
Salary: £140K – £250K + Equity
Company Description: Fyxer AI - Series A pure-play applied AI company backed by Marc Benioff, Madrona, and Lakestar.
Job Description:
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.
Location: London, UK
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.
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.
The ideal candidate:
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.
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.
Next steps
Step 1. Visit our website.
Step 2. Click 'Talk to Jack'.
Step 3. Talk to Jack so he can understand your experience and ambitions.
Step 4. Jack will make sure Jill (the AI agent working for the company) considers you for this role.
Step 5. If Jill thinks you're a great fit and her client wants to meet you, they will make the introduction.
Step 6. If not, Jack will find you excellent alternatives. All for free.
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.
Skills Required
- 5+ years of experience in shipping production software
- Expertise in TypeScript or Python
- Experience with AI/ML solutions including LLMs and embeddings
What We Do
Jack & Jill AI is an AI-powered recruiting platform that automates the job search process, offering assistance with applications, interview preparation, and job matching. It also helps companies find suitable candidates.
