Forty clients' books, forty containers, forty Drives mounted

A bookkeeper runs forty small-business clients. Each one keeps receipts and bank exports in their own Google Drive or Dropbox. The bookkeeper used to be logged into all forty on one laptop, switching accounts, praying nothing got saved to the wrong folder.

Now each client has a container. The client's Drive is connected once as a files backend, mounted into that container's filesystem, and it stays mounted across restarts. LibreOffice Calc runs on the container's display with the ledger open. Client twelve's receipts are physically unreachable from client thirteen's container.

Forty containers on one flat-rate bare metal server. Most are idle until month-end, and idle ones cost nothing extra. The bookkeeper opens the display URL for whichever client is due, works, closes the tab.