AI Engineer (Full-time)

Job description

About

About Lemrock

Tomorrow, in an agentic world, it won’t be humans browsing and buying on the web anymore, it will be AI agents acting on their behalf. A massive replatforming of the web is currently underway, and Lemrock is building the infrastructure to power that shift.

We are a deeptech startup specializing in agentic commerce : we enable brands (Leroy Merlin, Lidl, Rakuten…) to sell their products directly within conversational agents like ChatGPT.

We're taking the fundamentals from Criteo (models, performance, rapid iteration) and applying them to new AI interfaces. Jean-Baptiste Rudelle, co-founder of Criteo, is an investor and board member.

We're the first to operate this channel at scale , with a proprietary stack and concrete results:

·  100+ million conversational interactions analyzed monthly
·  60+ brands onboarded
·  Multi-million fundraising from top-tier investors

Job Description

Context

You'll join a tight-knit team with high product standards and direct access to production deployment : our models are tested in real-world conditions, with several million users each month, with very short cycles between prototyping, integration and deployment.

In this context, you'll work on the next generation of agentic and recommendation systems — building the pipelines, agents, and models that sit at the core of our product.

Your Mission

Your goal is to build and scale the agentic infrastructure that powers Lemrock's commerce intelligence — turning raw signals into automated, self-improving systems at production scale.

Concretely, you will:

· 
Analyze large-scale conversational interaction datasets (100M+ events/month) to uncover behavioral patterns, intent signals, and performance drivers.

· 
Design and deploy agentic pipelines end-to-end — from data ingestion and enrichment to model orchestration, monitoring, and continuous improvement — integrated into systems exposed to millions of requests daily.

· 
Build autonomous agents that keep our knowledge infrastructure accurate and current.

· 
Translate insights into iteration loops in production , by updating, fine-tuning, and improving our existing recommendation and ranking algorithms with tight constraints on latency, robustness, and business outcomes.

· 
Design and train new recommendation models from scratch when needed, with a focus on scalability, evaluation rigor, and deployability in real-world traffic.

Preferred Experience

Candidate Profile

· 
Strong academic background (MVA, ENS, X, Central…)

· 
2+ years of experience in AI, Agentic Systems, ML / Deep Learning, statistics or NLP

· 
Experience prototyping and deploying AI models into production

· 
Experience with production systems (APIs, monitoring, optimization)

· 
Strong interest in LLMs, recommendation and conversational systems: building agentic pipelines, agent orchestration, fine-tuning

· 
Comfortable with AI coding tools (Claude Code, Cursor)

· 
Thrives in ambiguity and 0-to-1 environments

· 
Fluent in English; French is a plus

Tech Stack

ML/AI (required)

· 
Agentic frameworks (e.g., Langchain) and/or native SDKs like OpenAI/Anthropic

· 
Observability and evaluation for LLM/agent workflows (e.g., LangSmith)

· 
Vector search, scoring, prompting, LLM orchestration

· 
Hybrid recommender systems, causal inference, probabilistic models

Bonus (appreciated but not required)

· 
TypeScript

· 
Engineering: Docker, GCP, PostgreSQL, Redis, Vector DBs, PostHog

· 
CI/CD

Recruitment Process

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

Additional Information

·  Contract Type: Full-Time
·  Location: Paris
·  Education Level: Master's Degree
·  Experience: > 2 years
·  Occasional remote authorized