# The design engine, first stage 2026-09-12 · Product > A brief becomes an interface that is generated, built in your container, measured and scored, with a preview address for every version. The engine plans a brief, generates source, builds it in your container, and measures the result against mechanical checks before a model looks at a screenshot. Each round writes a version, and each version has a preview address. Two of the day fixes were routes that existed and could not be reached. One router was mounted under `/api` while its own paths were written without that prefix, so a working feature answered with 404. The other registered a job handler in the web process, while only the worker process runs jobs. From outside, both look like a feature that is switched off. Neither was.