While metalcore is not something I generally listen to much anymore, I am very familiar with the subgenre.  Nice song man!  On this one, you've incorporated some elements that separate it from the stereotypical metalcore structure.  Namely, your harmonized leads around 1:36, and that riff around 1:53.   I'm usually a sucker for anything harmonized, and those leads were a nice touch!  I very much liked your chord choices around 1:53 as well -- I was thinking that at that moment (1:53), a slight volume increase on the guitars via automation might be cool.  

As for areas for potential improvement --  at around 2:17 it seems like the instrumentation was competing with itself for sonic space a little.  There was some leady stuff going on in the background there that was hard to hear.  You might consider playing with automation there to lower the level of the rhythm guitars a bit or raise those leads to give everything a little more room to breathe.  Finally, as far as a mix goes, it sounded nice to me -- but the drums were ever so slightly too low in the mix at certain points.  Within the genre, drums should sound really fat and punchy.  Some bands take it too far, but I think with some careful compression tweaks and maybe a slight boost to around 80hz on your kick drums, you could fatten up the drums a bit and make them sound bigger.  Not necessarily much louder, but just a bit fatter and a slight boost to volume.  Just curious -- how did you get those really low/sub-octave bass hits?  I have a spot in one of my songs that I might try to incorporate that sound.  Anyway -- nice song all in all.  I enjoyed!   

Here's some of my latest work if you'd like to give a critique -- I'm mostly looking for a mix critique, as the song I linked is only a couple minutes of a 9 minute song I'm almost finished with.  Here's the link if you'd care to comment:     https://www.ultimate-guitar.com/forum/showthread.php?t=1742604#1
Atmospheric dark metal w/ black and death metal influences:
(My Soundcloud page):

Pestilential Flood
Hey man, nice intro! Gets you going straight from the off. I like the use of strings and piano as it helps to differentiate it in a genre that can sound stale at times. Very strong vocals. There were definitely enough changes to keep it interesting and different from other songs in the genre. I agree with the comment above that the drums could be slightly louder but it is a minor gripe. The mix and production are otherwise very nice.

C4C? https://www.ultimate-guitar.com/forum/showthread.php?t=1741612#2