I was thinking that with ViaBTC being such a popular pool that they have a far better server implementation surrounding things like the process of propagation and higher spec hardware.
Nope.
It's purely the size of their total hash rate. As far as infra goes, Kano actually has better network block distribution than most much much larger pools do. It is not that difficult or expensive to setup but most pools do not bother because network distribution mainly only matters in an orphan race (which are fairly rare).
As far as work generation goes - again not that complex or hard to do right. Safe bet that Kano's extraordinarily high-performance main server at least matches what
any large pool is running and it certainly far exceeds -ck's setup...