Ranged vet
 Veteran Build - Warhammer 40k: Darktide 

This build revolves around tons of Recon Lasgun damage with a high crit-rate. 

Positioning is important to stay out of harms way, so you can unload on specials/elites/frontline.
The lasgun will absolutely melt carapace so do shoot them as well.

3x stamina curios seems wild, but with the Deadshot talent we get 25% crit chance so long as you have stamina. 
Dodge sideways while shooting to activate 'Duck and Dive' and keep 'Skirimisher' at 4 stacks for extra damage.
While your toughness is minimal, the 'Iron Will' talent will handle most hits you take very well leaving you with no health damage. Position well and you can afford to get hit once and then escape danger - this talent allows this build to have 3x stamina curios.

It can get a bit rough when melee horde stops you from shooting when they come from behind, as the team is rarely there to cover your back while you shoot, so this build is still figuring out how to circumvent that.

Knife has 80 mobility stat which can seem odd, but I find that I'm practically using ranged fire 80-90% of the match, so the knife is more of a getaway tool as well as applying bleed to captains and whatnot (melee weapon still undecided, maybe there's a better alternative).