You might be surprised to find out how CPU-intensive even something as simple as a DB request can be. Your driver has to do the work of communicating with the D

You might be surprised to find out how CPU-intensive even something as simple as a DB request can be. Your driver has to do the work of communicating with the DB server via its protocol, which is similar in cost to any other network request. More importantly, it has to deserialize the result and marshal the data into objects on the managed heap. Most DB drivers don't support streaming, so for larger requests you have to read all the data into memory, then convert it all into objects at once. And that's not even taking into account frameworks and ORMs like Hibernate, which itself can multiply the CPU used several-fold on top of JDBC, or whatever lower-level interface it wraps. I've never measured frameworks in dynamic languages, but I have no reason to believe they aren't similarly inefficient. And, yes, one of the optimizations I did for my reverse proxy app was to upgrade the JSON library, which brought a significant performance boost. But it's not the only source of CPU usage for apps, nor was it the only major optimization I successfully applied.