The most important API you’ve never heard of
ah HL7.> I hope you like XML documents, flat files, pipes and hats, SOAP, and even CORBA.Completely true.  But that's not really the problem.  You can download an HL7 or XML-parsing library and the dirtiness of the representation is converted to JSON or whatever works for you.The problem is API loopholes.HL7 does a pretty fair job defining what concepts get put into which fields.  However, many implementations ignore the computer-readable fields and literally dump everything as 80-character human-readable console outputs in the "custom text" fields.  Want any structured data?  You're gonna have to write a text parser specific to the hospital's legacy console systems.There's also a good deal of standardization over how things SHOULD be presented (ICD-9 etc), but those are ignored.  Often times physicians or pharmacists just type the drug into a free-text box.  5 different spellings of Ampicillin are the least of your worries -- it gets bad when the dosage is mixed in with the name, and it gets worse once you get into compounds or mixes.  The standard isn't the problem, its the data mapping problem for all the human-inputs.And then you get into fun stuff where billing people use different codes than everyone else for the same drugs, procedures, admissions, etc (there's a reason billing admins are so highly paid... it's a black art where you get creative how you describe things to the insurance companies).All of this is to say that I would love to see a RESTful, well-modelled API over HL7 messages, but the problems go far deeper than the protocol spec (and that's just for technical side of things... the politics and business threats of open APIs that the article talks about are completely true as well).  It's been a couple of years since I've been in the space and not at all familiar with these new FHIR specs, but I wish that process all the best.  If you're looking for a real challenge, it's not picking up Clojure or whatever is the language du jour... a true challenge is doing anything in healthcare.