Description
A design harness that turns Datamaran's design judgment into rules AI agents and engineers can read: used to build production screens, and as the environment every prototype runs in.
Short read
In 2026, I worked on a design harness for Datamaran's product team: a written layer of design judgment that tells whoever writes the code (a designer, an engineer or an AI agent) which component, props, tokens and rules to use before they start. Shipped screens were drifting between modules because the rules for headers, breadcrumbs and actions were scattered across documentation files, packages, prototypes and Figma documentation, with no single source an agent could read, and prototypes were rebuilt from scratch on every spike and didn't look like the product. The aim was to write that judgment down once and make every screen, shipped or prototyped, start from it. This involved building the harness around a pattern library, sourced from shipped code, where each recurring UI pattern is defined with its exact components, props, tokens and rules, so agents and engineers build production screens from it. It also involved building a prototyping shell that applies the same harness as an environment: the full application frame, the ESG domain as typed mock data and a machine-readable design spec. Production screens now start from one written baseline that reviews can cite, and feature explorations that used to take several days now fit in one working day.