This is great. I am working on a robotics application and this seems like a better abstraction than alternatives such local messaging servers. How do you deal with something like back pressure or not keeping up with incoming data?

The lib is based on channels and inherits the channel behavior in terms of backpressure. Simply put if no-one reads on one side of the pipeline, it wouldn't be possible to write anything on the other side. Still, it's possible to add buffering at arbitrary points in the pipeline using the rill.Buffer function.