AI Engineer (Contract)

Nabla; Paris; On-site; EUR 74,000 - 129,000; Full time

Job summary

Lemrock is accelerating its product where shoppers talk to AI agents before buying. As our freelance AI Engineer, you will dig into our data to find what drives conversion, then build the pipelines that act on it. You will work directly with the founders and the product and engineering teams.

Understand data sources, turn raw conversations into signals, train small models, and size their impact. Design agentic pipelines, measure with AB tests, and ship improvements to production when you can.

Qualifications

• 3+ years of experience in data science, with progression to LLMs and agents.
• Built agents or LLM pipelines and measured their success.
• Solid data science foundations: SQL, Python, statistics, A/B testing.

Responsibilities

• Understand what drives conversion by analyzing conversations, events, and metadata.
• Build agentic pipelines to prioritize products, prepare them, and improve recommendations.
• Measure changes with A/B tests and evals; feed results back into the loop.
• Ship production changes yourself when possible; otherwise hand off to engineering.

Skills

Data science

LLM pipelines

SQL

Python

A/B testing

Statistics

Autonomous

French + English

Tools

BigQuery

PostHog

Job description

Who we are

Lemrock builds the infrastructure of agentic commerce.

Tomorrow, consumers won't just buy on e-commerce websites. They will discover, compare and purchase directly inside conversational AI interfaces like ChatGPT, Perplexity, and a growing long tail of specialized AI assistants.

For brands, this is a major shift: if they are not present in these environments, they become invisible.

Our mission: enable any brand to exist, sell and distribute in this new channel.

We raised a €7M seed round (the first in Europe on this market), with Jean-Baptiste Rudelle, founder of Criteo, on our board, and the Bpifrance DeepTech label.

Today, Lemrock is already:

• 100M+ conversations per month

• 150+ brand clients

• a $100B market structuring at high speed

The role

We are accelerating. The product works, clients renew, the market is taking shape. Every day, shoppers talk to AI agents before they buy, and conversion has been at the heart of how we build the product from day one. We now want to go further and faster: understand precisely what turns a conversation into a purchase, and build the agentic loop that keeps improving it.

As our freelance AI Engineer, full-time, you will dig into our data to find what drives conversion, then build the pipelines that act on it. You will work directly with the founders and the product and engineering teams.

Understand what drives conversion

• Explore every data source we have: conversations, web and behavioural events, conversion tracking, product and advertiser metadata

• Turn raw conversations into usable signals (intents, categories, features)

• Train small models when they explain what drives purchases better than an analysis would, and size the impact of each lever

Build the improvement loop

• Design and build agentic pipelines that turn these findings into changes: which products we prioritise, how we prepare them, what we recommend, how our agents answer

• Measure every change with A/B tests and evals, and feed the results back into the loop

• Ship it to production yourself if you can; otherwise the engineering team integrates it

Strengthen what we measure

• Specify the events and properties we are missing, for the engineering team to implement

Must-have

• 3+ years of experience, typically starting in data science before moving to LLMs and agents

• You have built agents or LLM pipelines yourself, and measured that they worked

• Solid data science foundations: SQL, Python, statistics, A/B testing, classic machine learning

• Autonomous: you find the right questions in an open problem

• Fluent French and professional English

• Available now, full-time

A plus

• Conversion, CRO or funnel work

• E-commerce, advertising or marketing experience

• You have integrated your own pipelines into production

• NLP on real text data

• BigQuery, PostHog

• Startup experience

The mission

• Freelance, full-time, starting ASAP

• Around 3 months, while we hire permanently

• For the right person, the mission can turn into a permanent role

• Our stack: BigQuery, PostHog, Python

Why join us

• Join a company in early breakout mode, already generating revenue, with a clear technological edge and strong financial backing to fuel its growth

• Work directly with an experienced team: two repeat YC founders who've scaled product & tech before, a former strategy/innovation director (10 years in the sector), and ex-strategy consultants (McKinsey QuantumBlack, BCG)

• Be part of the next structural shift of the web: agentic interfaces

• Own mission-critical topics, grow fast, and shape the company's future trajectory

Daily rate discussed during the process.