Over the course of this book, we have seen how much the performance and scalability of an application matters inside an enterprise environment; with this in mind, we dedicated a significant portion of the book to understanding how to build an application that is not only performant but is also scalable.

So far, we have just seen some best practices for what we can do to build a performant and scalable application, but not how to figure out whether a particular piece of code in our application is slow and what might be causing it.

For any enterprise-grade application, improving its performance and scalability is an ongoing process, as the user base of the application keeps growing and the application's functionality continues to get more and more sophisticated. All of this effort requires an understanding of what is going on inside the application and on which parts of the application we need to focus for possible optimizations that can give us significant results.

In this chapter, we'll look into loopholes of how we can point out which portion of our application is turning out to be a performance bottleneck, and how we can build our application in such a way that we are able to track down the potential bottlenecks quite easily.

Over the course of this chapter, we will get to learn about the following:

• The behind the scenes of performance bottlenecks and their causes
• Profiling bottlenecks inside the code base
• Building an application with performance profiling built into its core