I had an old device that spit out some odd format serial data I wanted to log recently. I pulled out an random ESP8266 on a tiny board from a drawer and quickly wrote some code to read a single pin for the Rx. I didn't have any memory onbaord to store anything, and figured it would be cool to just dump this data onto my network and use something else to check what the current value being reported was and log it on another machine.
I could have used any number of packages that would create a little host on the ESP8266, or something that sends out MQTT packages to another server, etc etc.
but you know what was quickest? Telnet server on port 23, open, blasting out the buffered serial data once every second. It just sits there and does this. And if I want the data I just point a dashboard to that IP at that port and out it flows. If the device loses power and reboots, it is back up in a fraction of a second.
Security? who cares. it's some random numbers on my internal home network.