Saboteur Vet
 Veteran Build - Warhammer 40k: Darktide 

A do everything speedy Vet build. Use the wide swipes of the Mk VI Combat blade for trash mobs, and the heavy + push attack and punch stab for tankier enemies. The AOE explosive rounds of the Mk VI Bolt Pistol staggers enemies both close and far to give you and your team some breathing room. Good for a quick hipfire to get dogs and mutants off teammates too. Lethal Proximity on the Bolt Pistol buffs the grenades, and Run 'n' Gun allows for quick swap and hipfire on the move. I tried using Puncture and the Mk IV Bolt Pistol for better breakpoints, but it ultimately felt better to be able to stay mobile for me. I may drop Serrated Blade in favor of Field Improvisation for better teamwork. EDIT: I switched the BP second blessing to Deadly Accurate. This allows me to main my knife, get three kills, then when I need to take out a specialist or elite, switch to the BP for a quick headshot for +100% crit weakspot damage. I also gave up Serrated Blade for Field Improvisation for better teamwork and grenade spams.

Ideally you can maximize the damage buffs from the Weapon Specialist keystone by killing 3 enemies and swap to the Bolt Pistol for a guaranteed crit. This will also reload one round from the Always Prepared node (killing 1 enemy will always load 1 round, 4 kills for 2 rounds, and 9 kills for 3 rounds for the Bolt Pistol). Agile Engagement will also buff the Bolt Pistol critical shot, along with the Skirmish stacks you have. So it is quite powerful.