Common culprits for bad performance

Before we go into the details of profiling, let's first discuss the typical reasons for bad performance in applications.

In practice, many performance problems are pretty common and reoccurring. Knowledge of potential culprits is essential in choosing the right profiling strategy. Also, some specific culprits may manifest in recognizable patterns. If you know what to look for, you will be able to fix obvious performance issues without a detailed analysis and save a lot of time on further optimization attempts.

The most common reasons for experiencing bad application performance are the following:

• Excessive complexity
• Excessive resource allocation and resource leaks
• Excessive I/O and blocking operations

The most dreaded culprit of application inefficiency is excessive complexity, so we will discuss this first.

Code complexity

The first and most obvious thing to look for when trying to improve application...