Modern do it all lasgun build
 Veteran Build - Warhammer 40k: Darktide 

Modern problems require modern solutions. 

This is a pretty meta build centered around grabbing as many essential nodes as possible. It is built with lasgun/headhunter rifle in mind. 

Choice of melee weapon is based on personnal preference. Reciprocity can be swapped for Close Quarters Killzone if you play a slow large swings weapon that kills stuff before you dodge their attacks (cf powersword or chainaxe)

Spam as much voice of command as you can to support your team (pressing F when you hear a sniper or a pox burster activate should become a reflex, as the gold overshield negates health damage from them), snipe and stab stuff, don't forget to use your nades (try to always stay at 2/3 so you don't lose value on Demolition Stockpile)

If you want to use a fast firing weapon (accatran, meta god colomnus), simply remove Longshot, Determined and Marksman and use those three points to grab Onslaught.