Startrack (http://gps.gt/) is looking for a dev interested in working with Kotlin and Rx or Coroutines + Netty to update TCP/UDP device drivers written in a synchronous style. (We've ported part of them to Netty + state machines years ago, but found at the time that the complexity added to the code was not worth the marginal improvement in resource use). We are located in Guatemala + Poland. You can be somewhere else, but some face-to-face work will be necessary.