Duffy & Shanley does a lot of web banner campaigns. Clients need to see final creative before they can approve it. The agency used to use an HTML template with Bootstrap styles, but on campaigns with a lot of executions (read: most campaigns), this involved a lot of re-linking. Enter Node.
I built a custom flat file CMS using Nuxt.js and Node. On the server side, directories are read and return a dir tree as a nested object. The tree requirements are forgiving, but roughly patterned after the way the agency organized files so that it'd be easy to just upload folders as-is.
Each project lives on an agency branded client page, for easy client access. Each project can preview unlimited executions, messaging, and sizes. A simple JSON text file makes it easy to change options the agency frequently used.