Key Facts

Remote From:

Full time

Senior (5-10 years)

English

Hard Skills

Large Language Modeling Banner Ads Architectural Design Python (Programming Language) Data Retrieval Non-Volatile Memory Google Analytics Enterprise Information Integration Continuous Delivery Evaluation Projects Application Programming Interface (API) Microsoft Dynamics CRM Google Ads AdWorks Elixir (Programming Language) Marketing Analytics Engineering Analysis

Other Skills

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Dealing With Ambiguity
•
Problem Solving

Roles & Responsibilities

4-8 years of hands-on experience building and shipping production ML systems, with deep expertise in RAG and LLM agents.
Strong Python and API development fundamentals, with the ability to thrive in a fast-paced, high-ownership environment.
Proven track record solving ambiguous technical challenges, ideally with exposure to adtech, marketing analytics, or Elixir.
Experience integrating models with live enterprise data sources (e.g., Google Ads, GA4, Meta Ads, CRM and analytics platforms).

Requirements:

Develop and deploy production-grade ML/LLM systems and agentic workflows with persistent memory and sophisticated tool-use capabilities.
Integrate models with live enterprise data sources including Google Ads, GA4, Meta Ads, and various CRM and analytics platforms.
Build and refine evaluation frameworks, retrieval systems, and fine-tuning processes specifically optimized for the marketing domain.
Take ownership of architecture and model selection as the most senior ML engineer on a small, elite technical team.

Jack & Jill

About Jack & Jill

Ok, I'll go first. I'm Jack, an AI that gets to know you deeply, what you’re great at and what you want out of your career. I then work to make that a reality – finding the best fit public job listings as they come up, supporting with applications, interview prep, and moral support. I also work together with my partner Jill to find off-market opportunities and introduce you directly to companies, just like a recruiter would. And I'm Jill, an AI that spends time with hiring managers and talent teams to really understand their company, their open roles, and who will thrive there. I work with Jack to find great fit people, like a headhunter with 1000x the network. Head to website and have a chat with us, we're always online.

Founded: 2018

Company size: 1 - 10

Website LinkedIn See all jobs →

Job description

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: ML Engineer

Company Description: Passionfruit - Series A AI startup ($13.3M raised) backed by Seaya and Playfair

Job Description:
As the most senior ML Engineer on a high-impact team, you will design and ship production LLM systems that automate complex marketing operations for Fortune 500 clients like PepsiCo and HSBC. You will build agentic workflows with persistent memory and tool use, transforming how global brands analyze data and execute campaigns.

Location: London, UK

Why this role is remarkable:

Take meaningful ownership of architecture and model selection as the most senior ML engineer on a small, elite technical team.
Work at a well-funded Series A startup ($13.3M raised) backed by top-tier investors like Firstminute Capital and Seaya Ventures.
Directly impact the marketing operations of some of the world's largest brands, moving them from manual "gut-feel" processes to AI-native precision.

What you will do:

Develop and deploy production-grade ML/LLM systems and agentic workflows with persistent memory and sophisticated tool-use capabilities.
Integrate models with live enterprise data sources including Google Ads, GA4, Meta Ads, and various CRM and analytics platforms.
Build and refine evaluation frameworks, retrieval systems, and fine-tuning processes specifically optimized for the marketing domain.

The ideal candidate:

Possesses 4-8 years of hands-on experience building and shipping production ML systems, with deep expertise in RAG and LLM agents.
Demonstrates strong engineering fundamentals in Python and API development, with the ability to thrive in a fast-paced, high-ownership environment.
Brings a proven track record of solving ambiguous technical challenges, ideally with exposure to adtech, marketing analytics, or Elixir.

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.