This is an alternative approach that would be done instead of T111729: Reproduce size-based JPEG sharpening logic in Varnish

The idea would be to write a plugin/monkey patch for thumbor that would let us hardwire the JPEG sharpening logic. This would take the form of a configuration option that would neuter any sharpen filter parameter passed if the target thumbnail size is less than 15% smaller than the original.

The advantages of doing this in thumbor are to reduce the amount of logic in our caching layer (varnish), that it would still provide expected results in case of cache degradation or when thumbor is directly exposed without a caching layer. Lastly it allows us to generate thumbnails without having to expose the original dimensions in the thumbnail URL.