Data Scientist (Contract)

Lemrock; Paris; Hybride; EUR 101 000 - 166 000; Plein temps

Résumé du poste

Lemrock is seeking a freelance Data Scientist (full-time) to dive into our data and uncover what turns conversations into purchases. You will work directly with the founders and product/engineering teams to drive measurable improvements and validate hypotheses with data.

Daily work spans natural-language conversations, behavioural events, and conversion signals; you will define signals, run experiments, and help shape the product roadmap as we scale adoption of conversational AI in commerce.

Qualifications

• 4+ years of hands-on data science or analytics impacting product decisions.
• Advanced SQL and Python for data.
• Strong statistics and experimentation, including A/B design.
• Autonomous with ability to define questions in open problems.
• Fluent French and professional English.
• Available now, full-time.

Responsabilités

• Understand what drives conversion across data sources.
• Turn raw conversations into usable signals (intents, categories).
• Link what agents say to user actions and drive product improvements.
• Design and run A/B tests, then read the results.
• Collaborate with founders and product/engineering teams.

Connaissances

SQL

Python

Statistics

Experimentation

Autonomy

AI tools

French fluent

English professional

Outils

BigQuery

PostHog

Description du poste

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, with someone fully dedicated to understanding what turns a conversation into a purchase, and to proving it with data.

As our freelance Data Scientist, full-time, you will dig into everything we have and tell us what drives conversion, what to change in the product next, and how to prove it. You will build on the work already done, challenge it, and find the levers we have not seen yet. You will work directly with the founders and the product and engineering teams.

Understand what drives conversion

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

• Turn raw conversations into usable signals (intents, categories, features) that you define and build

• Link what our agents say (answers, recommendations, tone) to what users do next, and turn it into concrete improvements for the agent team

• Find the next levers that move purchases, and size the impact of each one

Experiment

• Turn your findings into prioritised hypotheses the product team can act on

• Design the A/B tests that validate them, then read the results

• The engineering team implements the variants: you do not write production code

Strengthen what we measure

• Spot the remaining blind spots in what we measure and specify the events and properties we are missing, for the engineering team to implement

Must-have

• 4+ years of hands-on data science or analytics, with analyses that changed a product or business decision.

• Advanced SQL and Python for data

• Strong statistics and experimentation: A/B test design, causal reasoning, and the judgment to separate real effects from noise, selection bias and measurement artifacts, and to know when the data is too thin to conclude

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

• AI-forward: you use AI tools (Claude, Cursor, agents) daily

• Fluent French and professional English

• Available now, full-time

A plus

• NLP on real text data: classification, clustering, LLM-based labelling

• E-commerce or retail experience

• Conversion, CRO or funnel analytics

• BigQuery, PostHog

• Adtech or performance-marketing measurement (attribution, ROAS)

• Familiarity with ranking, recommendations or search relevance

• Startup experience

No school requirement.

The mission

• Freelance, full-time, starting ASAP

• 1 month minimum, around 3 months expected

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

• Our data 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.

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