In the last few years, the programming has changed drastically per the way hardware evolved, where parallel processing, real-time, cloud, and several other approaches have been introduced to achieve higher performance. Lambda expressions and streams received a heartwarming welcome in Java 8. Since then, they kept evolving, achieving performance by parallelism, laziness, and using short-circuit operations, but there is a downside as well, and we need to be very cautious while choosing Streams, as it may degrade the performance of your application. We're going to break down a small application and rewrite it (hopefully) to achieve better performance.