[lamosty]

Thanks for the kind words Justin, they are the hugest approval of my work so far. :) Not getting this in uni where everybody is about matrices and stuff.

Have you tried using HHVM instead of PHP-FPM? Although you are definitely having a fast site, HHVM could potentially double the numbers.

Yes, one slow DB query can ruin all the fun. That's why using Redis for in-memory DB caching can help. In some cases, it might be more optimal than using full page caching because DB caching works for logged in users too while page caching has to be bypassed.

Using JavaScript for better performance helps too, I like how you optimized that menu. I've noticed that profiling the code with, for example xhprof, can be really useful during development. Found myself doing some slow code/queries, ran the profiler and immediately discovered the bad parts. It's quite easy and straightforward to fix them if you know where they are.

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They probably meant that APC, which was a separate PHP caching module back then, is dead. However, caching is now part of PHP and as far as I can remember, it is using the same API as APC was, so basically it still lives and W3TC supports it.