- Email delay to Gmail inboxes for verifying an SSH key used via SSH via email is longer than the timeout of the "Waiting for verification email..." stage in the SSH key registration. Wait longer or provide a non-email way to authorize a new key. You could imagine a few ways to do this: Allow users to add/delete SSH keys from the website or exe.dev shell; create a bearer token/random string that I can generate from the exe.dev shell or website to associate a new SSH key; SSH key signatures (existing key signs new key); SSH CAs (like @cert-authority); etc.
  - SSH U2F/FIDO2 authentication support has become mainstream, and offers you a way to have homogeneous auth across web and SSH interfaces. Maybe consider unifying authN this way?
  - exe.dev ssh interface does not allow me to list SSH keys, only to delete them. Consider moving all authN/authZ functionality into an "auth" subcommand/submenu (like you have for "share") and support SSH pubkey CRUD in there.
  - You make some strong assumptions about email addresses that aren't true -- what happens on email address changes, lost email access, etc. This will become more important when you start billing (and possibly costly).
  - How do I manage persistent disks? Any way to attach them to a different VM after I'm done with them on the original one? Is there always a single PD per VM or can these be managed separately? What about data or database volumes? Can PDs be attached to one or multiple VMs at a time?