Founding Full-stack Software Engineer

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

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 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.

Candidate Profile

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)

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.

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