Scale all the things: 'Setup a caching layer (Memcached, Redis, Varish)'...if only it was just that easy.<p>Prep for scaling should be something like;<p>1. testing to see when you'll need to
2. monitoring so you know when
3. planning before you reach date / time from #2 how you'll do it
4. implement
5. test you've done #4 properly
6. release
7. repeat the whole process<p>Work out a methodical way that makes sense. "Setup a caching layer" is not that.