FULL-STACK SOFTWARE ENGINEER (FULL-TIME)

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 small, high-ownership engineering team building production systems that serve millions of users. We care deeply about code quality and clean architecture — and we intend to keep it that way as we scale.

Cycles are short, ownership is real: you'll ship to production within your first week.

Your Mission

Your goal is to build and ship the product that powers Lemrock's commerce infrastructure — with full ownership, from design to production.

Concretely, You Will

• Ship features end-to-end that reach millions of users — from data model and API design to the interface they interact with.
• Scale and harden our backend as traffic, integrations, and product complexity grow.
• Shape the architecture of the codebase — enforce clean boundaries, maintain modularity, and make decisions that compound as the team scales.
• Move fast across the stack — backend, frontend, infra, data — wherever the highest-impact work is on any given week.
  
  

Preferred Experience

Candidate Profile

• Strong academic background (top engineering school, CS degree), proven professional track record, or hands-on entrepreneurial experience
• 3+ years of hands-on software engineering experience
• Deep proficiency in TypeScript
• Experience with structured backend architectures (DDD, hexagonal, or similar)
• Has owned features end-to-end: data model → API → frontend → deployment
• Comfortable with AI coding tools (Cursor, Claude Code)
• Thrives in ambiguity and 0-to-1 environments — ex-founders or entrepreneurial mindsets are a strong fit
• Professional proficiency in French & English
  
  

Tech Stack

Core (required)

• TypeScript, NestJS, React
• PostgreSQL, Redis
• Docker
• Clean architecture patterns (hexagonal, ports & adapters)
  
  

Bonus (appreciated But Not Required)

• GCP (Cloud Run, Pub/Sub, BigQuery), Terraform
• Vector databases, embeddings, LLM integrations
• Domain-Driven Design (DDD), CQRS
• TanStack (Router, Query, Table), shadcn/ui, Tailwind, Vite
• Durable workflows (Inngest, Temporal)
  
  

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
  
  

Package

Competitive salary + equity disclosed during the interview process.

Additional Information

• Contract Type: Full-Time
• Location: Paris
• Education Level: Master's Degree
• Experience: > 3 years
• Occasional remote authorized