My 76yo Dad just used Claude Design to make a simple commercial tenancy/lease management CRUD app. We handed what he built to Claude Code to implement within my existing business tech stack. It perfectly followed my coding & testing playbooks (basically a multi-file CLAUDE.md with prompt & command hooks to evaluate conformance). It works… exactly as my Dad imagined.
Now, mind you, my Dad had some outdated UI expectations (he asked Claude Design to style use a Windows 98 aesthetic!), but my point is: we just built a fully-functional, deeply tested, domain-expert-designed app, in less than a day.