Residual Labs Verified Company

Residual Labs is an engineering lab based near Paris, France, working in French and English, with specialist partners brought in when a project needs a voice, a camera or extra hands.

The lab exists because of a pattern most business owners recognise. A project is commissioned, a demo impresses everyone in the room, and a year later nobody can change a line of it without breaking something else. We build for the second year rather than the first meeting: systems that carry real load, document themselves, and can be handed to another developer without the original author sitting next to them.

Our work covers nine families, from a paid diagnostic through to a deployed application. Digital strategy and presence audits. Brand identity and design systems. Commercial documents and content. Websites built to convert, in React and Next.js. Motion design and video. Customer relationship automation, telephone included. AI assistants and custom software. Developer tooling, meaning CLI, SDK, API and MCP servers. Technical SEO and visibility work, including optimisation for AI answers.

Three of our own products run in public and double as proof of method. SPARDA adds deterministic verification to code written by AI and is published on npm. Residual Audit scans a website and returns a report a non-technical owner can read and act on. Residual Reach structures outbound campaigns while the contact database stays with the client.

We also publish our research, time-stamped and citable: four deposits on Zenodo (CERN / OpenAIRE), each with its own DOI, on relativistic dynamics, idempotent projection over tree schemas, AI alignment and computational complexity. ORCID 0009-0005-7604-4709.

Pricing is public. The catalogue lists 89 referenced deliverables across those nine families, plus fixed packages. Every engagement is scoped in writing before it starts and ends with sources, documentation and a handover, never with a login to something we control.