alphagov/whitehall — comment on commit 25cd2f7e0713ecc40a7f9f2140b1e8a463d76a6c
File:  line 0
By tomafro:

Luckily don't have to worry about different browsers, as all public facing requests go through varnish. It appears as though varnish uses its own version of the document for `max-age` seconds, then sends a new request with an `If-Modified-Since` header, allowing the server to respond 304 if it wishes. Which is exactly as I'd hope and expect (but always worth trying).