HikariCP is a connection pool software that maintains connection pool resources so your code use them to access databases.
This can be used in place of Akka and Scala execution context for database connections. This helps keep your main application code from being blocked while it does a database query to either store or retrieve information.
HikariCP is the fastest and most resource efficient connection pool technology for the JVM.
Introduction to HikariCP – a great introduction to what HikariCP is to start out with.
HikariCP documentation – a link to the actual documentation, you have to click the version of CP you want to use.