One time to seriously consider using UDP is when you find yourself implementing "UDP on top of TCP", e.g. implementing what's essentially a small-packet messagi

One time to seriously consider using UDP is when you find yourself implementing "UDP on top of TCP", e.g. implementing what's essentially a small-packet messaging protocol that uses TCP underneath. I find it disturbing when I have to reassemble messages read from a TCP socket and if the messages are small enough to fit into a UDP datagram I feel like I'm better off with UDP plus a lightweight retry mechanism.