Elixir and Nerves let you build and launch IoT systems in record time, but you've still got the vast sea of the internet between you and your devices. At SparkMeter we run servers that tell embedded devices how to do things and embedded devices that tell servers what they did. All of this needs to happen throughout normal development cycles, unreliable power and network connections, and hardware (and humans) that always seems to surprise you. This talk explores some of these challenges, some of the options to work through them, and some of the ideas behind SparkMeter's event-based communication solution, Sink.