1. Set proper caching headers (`Pragma: cache`)
2. Resize image proportionally to a max size of 1920px
3. Store images with progressive mode
This resizes a previous 2.8 MB picture to 300kb and makes it rendering going down from 11 seconds to less than 1 here. And future requests won't have to download the file newly.
Lukas Reschke
Arthur Schiwon
Julius Haertl
Joas Schilling