first of all, CONGRATS! that sounds really cool. imo communication with the other artist is key. taking some time to find out what you both bring to the table, and what both of your visions are, will help a lot. get familiar with his other work if u arent, and encourage him to do the same!

get contracts, get payment arranged in writing. if anyone says "we don't need a contract, u can trust me," that's a pretty big red flag, but im guessing things are on the up and up there. for basic Industry(tm) stuff, one of the managers of Heroic Records has a lot of good resources. basically, now that there's money being exchanged, it's a good idea to treat it like a job, albeit a job that you enjoy a lot.

Really like the snaps and the gated pluck synth at the beginning, they both fit with the vocals really well. I would say maybe add some additional high end on the snaps, and the vocals seems just a bit subdued, but neither are a huge issue.

Holy nice drop, Batman.
Absolutely love the vocal chopping/mixing work. The snap right before the bass was awesome as well and really fit the vibe. There's good synth work underneath, and I love the little additional effects at the end of every 4 bars - especially the little percussion hit riiiiiight before 1:00.
I actually don't think the bass sounds too bad either. I would say sidechain it to the kicks and stuff to give it more variation and life, but it's really not bad otherwise.

Really nice track man, I love it! Mix the final and you are good to go. Nice work with this one.

Really solid idea here. Build and drop parts sound really nice.

In terms of the break, it seemed a little barren. I know it's a fast breakdown, but some louder, more dynamic sounds would be good.