Parsing JSON Really Quickly: Lessons Learned

I can relate. I have been one of those who started writing a CSV library and went down the rabbit hole of edge cases and configurability. Looking back (and only thinking on productivity) my time would have been better spent doing something else. I did, however, learn quite a lot along the way: - how text is represented in a computer (and all its caveats), - how to identify and tune slow code, - how to vectorize code (thanks to Daniel Lemire's this video ), - how to encapsulate code better, - how to use some great CSV tools out there (thanks to Leon's link ) - how to better manage and communicate an open source project. All in all, I am still not sure it was a mistake. Moreover when Swift didn't really had, at the time, a good Codable interface to CSV. Next time I encounter a similar problem I will probably just wrap a C library and create a good interface, though. In any case, if you are coding in Swift and find yourself in need of a CSV encoder/decoder, you might want to check link

I find these optimizations fascinating. Anyone familiar with Lemire likely knows about this, but I listened to a podcast episode[1] with him a few days ago and learned about `simdjson`, the tool he authored that parses JSON at 25x the speed of the standard C++ library.[2][3] It's worth looking at if you're into this sort of thing. 1. link 2. this video 3. link

Daniel Lemire has an interesting talk on this: this video . They key takeaway is that the disk is rarely the bottleneck.