Founding Full-stack Software Engineer

Who we areLemrock 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 month150+ brand clientsa $100B market structuring at high speedContextYou'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 MissionYour 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 ProfileStrong academic background, proven professional track record, or hands-on entrepreneurial experience2+ years of hands-on software engineering experienceDeep proficiency in TypeScriptExperience with structured backend architectures (DDD, hexagonal, or similar)Has owned features end-to-end: data model → API → frontend → deploymentComfortable with AI coding tools (Cursor, Claude Code)Thrives in ambiguity and 0-to-1 environments — ex-founders or entrepreneurial mindsets are a strong fitProfessional proficiency in French & EnglishTech StackCore (required)TypeScript, NestJS, ReactPostgreSQL, RedisDockerClean architecture patterns (hexagonal, ports & adapters)Bonus (appreciated but not required)GCP (Cloud Run, Pub/Sub, BigQuery), TerraformVector databases, embeddings, LLM integrationsDomain-Driven Design (DDD), CQRSTanStack (Router, Query, Table), shadcn/ui, Tailwind, ViteDurable workflows (Inngest, Temporal)Why Join UsJoin a company in early breakout mode, already generating revenue, with a clear technological edge and strong financial backing to fuel its growthWork 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 interfacesOwn mission-critical topics, grow fast, and shape the company's future trajectoryPackage