[nmjenkins]

Or you could … just build it directly on indexedDB. That's what we did for our offline support at Fastmail, with just a small wrapper function to make the API promise based: https://www.fastmail.com/blog/offline-architecture/

The performance has been pretty decent, even with multi-gigabyte mailboxes.

[idle_zealot]

The offline support has been great. I used to have to keep another mail app synced with my fastmail inbox over IMAP just in case I needed access to an email and had crappy connection. Now I can just have the one email icon on my homescreen.

[isaachinman]

Saw that Fastmail released offline support recently, nice work!

Do you not have any need for CRDT?

[nmjenkins]

No, CRDTs wouldn’t be useful right for what we currently do. If we ever wanted collaborative text editing for something then we’d use them for sure.