Full-stack Software Engineer (Contract)

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. As our freelance Full-stack Software Engineer, full-time, you will work inside the team like any of its engineers: same codebase, same standards, same ownership. 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. From day one You push your first code to production within your first days, then ship every week You write excellent, well-tested code the team can build on You are reliable: when you take something on, it gets delivered Candidate profile Strong academic background, 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 Uses AI coding tools every day (Cursor, Claude Code) Thrives in ambiguity and 0-to-1 environments: ex-founders or entrepreneurial mindsets are a strong fit Professional proficiency in French