[minhmeoke]

The problem with email attachments is that they only support files up to around 25MB, while slack has a 1GB attachment limit, and if you have a slow uplink to the cloud, it could take a while to upload the file.

A friend wrote a faster and more sophisticated version of `python -m http.server 8000` in rust which also supports uploads, you can read about here: https://news.ycombinator.com/item?id=37628347

File transfers are performed over the local network, and therefore should be very fast. If you don't have a network connection, you can just enable a Wifi hotspot on your mobile device and transfer the files over that. There is no need to install any software on the mobile device, you can just use a web browser to browse to a directory that you share over the network.