A single box?! Do we know its specs?
FreeBSD 10.1
Nginx 1.7.10
Racket 6.1.1 with some HN and FreeBSD specific patches.
2x 3GHz Intel Xeon-IvyBridge (E5-2690-V2-DecaCore)
8x16GB Kingston 16GB DDR3 2Rx4
SuperMicro X9DRI-LN4F+_R1.2A
Adaptec 71605
9x 1000GB Western Digital WD RE4
2x 200GB Smart XceedIOPS SSDYou can do all of it locally (except multi zone and multi region reliability) but it would take a lot of configuration, skills and you wouldn't have the same Gui for everything.
AWS is not cheap but companies don't care, because without it, you have to pay to find experts and keep them happy, which is a lot harder.
Some older discussion on the topic here: https://news.ycombinator.com/item?id=3165095
FreeBSD 11.1-RELEASE-p4
CPU: Intel(R) Xeon(R) CPU E5-2637 v4 @ 3.50GHz