the strongest skitarii build
 Skitarii Build - Warhammer 40k: Darktide 

Im not a pro player but im good with numbers. I have managed to build this tree so it has essentially 0 wasted nodes, every single one either improves your damage or survivability with all nodes having near constant uptime. The scoreboard image was only a auric malestrom mission although i have completed h40 with this build too.

There is no special way to play this build other than being on the front line tanking damage and killing hordes. Your nodes are self sustaining and you should be able to maintain max stacks on all of them passively without any special techniques as long as you are in combat.

WHY IVE PICKED NODES AND ALTERNATIVE OPTIONS
Noospheric command is essential, it provides you with the stacks of ranged buffs passively, especially with the auto mark mod which i highly recommend tuning to the most problematic enemies to not only significantly improve your survival but also that of the entire team. It also maintains your stacks of flensing in the process, even when taking constant damage if there are a lot of enemies these should generate faster than they dissapear. 

I opted for flensing protocols because of its synergy with noospheric command as well as the heavy buffs it gives, at max stacks of flensing on this build you get 20% damage, 20% toughness damage resistance, 12% crit chance, 12% attack speed as well as 5% extra capacitance for every elite killed which adds up really fast as well as being an effective cost reduction to noospheric command. Max stacks in my games has been easily obtainable even when taking tick damage due to the sheer number of elites and specials in games.

I chose Weakness analysis doctrine over Galvanic marking array just because i think the uptime will be slightly higher here. I do not think Retrubution conduit is a amazing choice because it will primarily only be in effect against bosses, and when im fighting a boss i use my blast pistol or chord claw. 

In terms of weapons the ones im using are more of a suggestion than i requirement, i believe what i have selected to be the best although this build should transfer well to different choices. For perks on curios, gunner damage resistance is something i chose because they annoy me, choose whatever you hate the most lol.

THE NUMBERS
As stated the primary goal of this build was node uptime, these numbers assume you have max stacks of everything but even if you dont, you should at minimum be close to these at all times. Heres a list of what you gain using this build.

DPS
+20% all damage
+10% all damage
+15% all damage
+15% melee damage
+15% ranged damage
+15% damage (from servo skull debuff) 
+12% melee attack speed
+12.5% melee attack speed

The following stats include the servo skull in the expected dps output
Overall expected DPS increase for melee: 1.6x (damage) x 1.245 (attack speed) x 1.15 (servo skull debuff) = 2.291 (129.1% increased dps not including our massive crit rate and damage)
Overall expected DPS increase for ranged: 1.6 x 1.15 = 1.84 (84% ranged dps increase)

From the tree alone we receive 25.5% crit chance (or 29.5% at 0 charges), combined with the transonic blades blessings and base stats that comes to 65.4% crit chance or 69.4% at 0 charges.

DAMAGE REDUCTION
 

+20% TDR
+15% TDR
+20% TDR
+15% TDR
+17.5% TDR
+15% General DR

0.8 x 0.85 x 0.8 x 0.85 x 0.825 x 0.85 = 0.3243 (rounded) adding to a overall damage reduction of 67.57% which translates to roughly triple toughness.
In terms of toughness regen, its extremely high and you can out regen pox gas in the right circumstances. No need for maths there.