Nothing is more disappointing than having to deal with issues in production when an application is behaving in an unexpected way. In this chapter, we are going to discuss some simple techniques that can be applied in order to get rid of these annoying problems, applying simple recommendations to your daily routine to take care of the performance of your applications. Throughout this chapter, we are going to review the following topics:

• Why performance matters
  • Scalability
  • Availability
  • Performance
• Key recommendations to keep your software away from performance issues
  • Profiling applications
  • SQL query optimizations
  • Load testing

Let's start by introducing the importance of performance.