Founding Full-stack Software Engineer

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.

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 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.

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.

E

• Strong academic background, proven professional track record, or hands-on entrepreneurial experience
• 2+ 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)

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.