First and foremost important thing, Achieving great performance on any web application is NOT the turnkey solution. OR it is not one-time activity. You need to continuously move forward inch by inch to achieve great performance for your drupal application.
Achieve better performance on Drupal website
Let’s get serious now. There are 15 steps which I have documented as since last 8 years of my Drupal development and Application management.
The easiest steps are listed first.