The candidates have already been selected.
I heard some statistics on this hiring round and I can tell you that they are not pretty.
600 applications for 30 places is underrated.
There were only 12 openings and the applications you can multiply them by 6 at least and add those who didn' t make it into the clogged mailbox.
Chances of individuals were in the 0.0X% range with 2<X<4.
If you don' t get an answer, give them a break.
They are certainly overwhelmed by the huge amount of triage work they are dealing with.