About Zap
This is minimal performance-focused theme for Ghost to demonstrate the baseline performance of Ghost as a platform.
Out of the box, Ghost is incredibly fast. It's generally very easy to hit scores of 100 across the board in Google Lighthouse, provided that the theme doesn't add a lot of overhead in the form of images, scripts, and other large assets.
Any score below 100 is a result of the theme you're using, rather than Ghost itself, and is possible to improve.