The proof-of-concept used a small game-simulation where browser Javascript applications where shooting balls at each other, using two websocket channels to 2 out of 5 servers in an Erlang OTP cluster. The Proof-of-concept demo involved pulling the mains plug out of one of the two, and observing no hickup in the game, and the game providing a small debug message "switching to other game server".
This fun project led to a large influx of Erlang programmers at Spilgames for a few years.
I executed this project remotely while on sabbatical.