fun over function
 Veteran Build - Warhammer 40k: Darktide 

This build skips crutches to set up fun plays.

• Executioner Stance is purely for wallbanging everything including ogryns. Agile Engagement's +25% damage and aiming at heads solves a bunch of plasma 1shot breakpoints, though you'll still need a god roll to get Crushers. Don't worry about it if you don't - they're more fun to saw up than shoot! (Point saved: Tactical Awareness, Relentless. You only do it for a wallbang every 30 seconds.)
• Smokes make specials walk straight into your axe and save time cleaning up shooters behind cover. Plasma's good at it, but you'd rather spend that time ripping and tearing with the axe. (Points saved: Grenade Tinkerer. With good flow you'll push past in 15 seconds and don't need the full 30. There's a variant that relies on Demolition Team instead of Demolition Stockpile but 1nade/60s is reliable in Damnation quickplay when Maelstrom isn't filling. The left branch is also more fun than the middle branch since it gives way more ammo! You can stop meleeing and go full plasma whenever you like.)
• Plasma is for +15% melee attack speed and +25% melee damage. You quickswap to pop cleaving shots at zombies or wallbang some elite, then quickswap back to rip and tear. The axe hits 1shot breakpoints so the damage bonus is only important for cleaving heavy swings. When chaining 1v1 kills with lights you're also limited by movement speed more than attack speed, so the attack speed bonus is only needed for groups. (Points saved: Exploit Weakness, Always Prepared. Reload-canceling the plasma gives you something to do in elevators and during lulls. And while you'll end up with ~40% crit once fully dodge-stacked it'll only matter on bosses.)
• Your survival comes from damage and mobility. Confirmed Kill keeps up chip damage from venting, Exhilarating Takedown stacks up toughness damage reduction when you want it. (You don't need Voice of Command overshield or Iron Will damage reduction if you spam push attacks, put your shoulder against objects, and hold chokes. I even run this with 3x +3 stamina curios - you have regular wallhack to spot pox bursters, just don't get blown up! ;)

This all assumes you enjoy and are comfortable with the chain axe. Aim your lights without swinging your camera so the latching mechanic doesn't jerk it around. They're the bulk of your damage, absolutely rip through maniacs, and are extremely safe 1v1 due to starting to stagger targets part way through. Heavies mulch up hordes when buffed by interspersed plasma shots, but don't be shy about spending ammo on zombies when you see good shots. You have a ton! Rev attacks are for carapace and mutant drive-by latch kills.

The one thing this build doesn't excel at is boss killing. Quickplay players avoid daemonhosts and the rest of the bosses are only threats if you're ambushed straight out of an airlock or something.