When it comes to application performances, bottlenecks like waiting too long for a specific page to load or triggering an API call which never returns – are easy to spot. In those cases it is obvious where problems are and where most of the execution time was spent. Of course, it is totally different thing, will you be able to resolve the noticed performance issues or not.
On the other side, there are many places in the application where time can be spent. Some used tools and libraries we take for granted and do not expect our logic is spending significant time running within them. This is a story about one specific case, in which application logic takes a lot of time to execute and how a simple change using HikariCP helped to cut the execution time in half.