A wired internet connection plus a mobile network with enough bandwidth to tether is sufficiently redundant for the average software engineer. Maybe throw in a

A wired internet connection plus a mobile network with enough bandwidth to tether is sufficiently redundant for the average software engineer. Maybe throw in a diesel generator/Tesla Powerwall if you're worried about power outages that last longer than your laptop's battery. If all three fail simultaneously, you probably have bigger problems than just internet connectivity.