I've recently started working with FHIR data. FHIR is a standardized JSON format for transmitting electronic health data.
jq is "a lightweight and flexible command-line JSON processor", which is the best tool I've been able to find for rapidly working with JSON data. Sure, there are lots of converters that allow you to convert FHIR JSON data to other formats, but for answering quick questions of the data, there probably isn't a better tool to help understand FHIR.
Unfortunately, after some googling, I haven't found much that describes how to use jq to manipulate FHIR data. So, this document will help me keep track of my findings and allow others to utilize what I have learned.
I will use this fake patient data to report results so that you can replicate my results exactly: https://github.com/sync-for-science/discovery-FHIR-data/blob/master/DSTU3/data/1396-Ledner.json