Patagobi uses WebRTC. When you create a room, you get a 6-digit code. When a receiver enters that code, your browsers connect directly to each other. Files are sent straight from one device to the other without going through a central server.
Technically, no. Since files are not stored on a server, there are no artificial limits. However, extremely large files might cause your browser to use a lot of memory. For massive files, performance depends entirely on your local device and browser limitations.
Yes. WebRTC connections are end-to-end encrypted by default. Because the files don't rest on an intermediary server, the risk of interception is extremely low.
Strict corporate firewalls or certain network setups (like symmetric NATs) can block peer-to-peer WebRTC connections. If both devices are on very strict networks, they may fail to connect.