Real per-customer isolation

On TDesk, every customer is a genuine UNIX user on the server. PHP runs as that user, and files are mode 0640 owned by them — there is no shared "nobody" account and no reading across accounts.

This is proper operating-system-level separation, not a soft convention. It matters the moment you host more than your own sites: a compromise or a runaway script in one account cannot reach another. It's the same isolation model serious hosts use, applied automatically to every account you create.