Performance and scalability determine how fast your application can serve a page and to how many users at a time.

Twig is a template engine for PHP, which is the language used in Drupal. Twig can be used to design templates in generic PHP applications as well as Drupal themes.

Web services allow two or more applications to share data and instructions with one another across the Internet.

Caching in Drupal is controlled by Drupal's Cache API which is used to store any type of data on a permanent or temporary basis. Some types of data tend to take a long time to compute, but utilizing the Cache API in your module can help your site load data more quickly.

Composer is the preferred dependency management solution for PHP, is used by Drupal core, and is becoming increasingly popular for managing the modules and themes used for a Drupal project.

For the Drupal developer, Docker is a way to provide a local development environment to run web server software.