Clojure has strong Java interoperability and underpinning, and due to which, programmers can leverage the performance benefits nearing Java. For performance-critical code, sometimes it is necessary to know how Clojure interacts with Java and how to turn the right knobs. Numerics is a key area where Java interoperability is required to get optimum performance. Type hinting is another important performance trick that is frequently useful. There are several open source Clojure libraries that make such activities easier for the programmer.
In the next chapter, we will dig deeper below Java and see how the hardware and the JVM stack play a key role to offer the performance we get, what their constraints are, and how to use the understanding to get better performance.