When running Google PageSpeed (https://developers.google.com/speed/pagespeed/insights/) we get warning about that the js files for find does not use expire date. 

Would be great it you could change that.

If you like to see how it looks for EPiServer World see this address:

https://developers.google.com/speed/pagespeed/insights/?url=world.episerver.com

You also have some work to do, like the rest of us  :-)