| > Swift is fast Not really. Apple's propaganda is fast, Swift can sometimes be almost kinda fast if the stars align just right, but in general it is quite slow. For example, last I checked, Kitura's HTTP parser is written in C. And has to be. Another one: the various JSON "parsers" that wrap the built-in NSJSONSerialization API add about an order of magnitude overhead. That is after all the actual parsing and conversion to a property list, which isn't exactly the most efficient representation in the first place. The Big Nerd Ranch guys realized that the only way to get a "high performance" JSON parser is to do it 100% in Swift. They did that and the result is significantly faster than the wrappers. And only 4x slower than NSJSONSerialization, which again isn't exactly a very efficient parsing model (think XML DOM parser). https://github.com/bignerdranch/Freddy/wiki/JSONParser I do a more in-depth analysis in my book, "iOS and macOS Performance Tuning" https://www.amazon.com/gp/product/0321842847/ref=as_li_tl?ie... EDIT: I forgot the link to Freddy |