The idea is to use Spike Trap w/ Scatter + Custom Engineering + Sharpshooter + cheap equipment focused on critical hit damage, do tons of damage with the traps before your 2nd attack and then use vault, caltrops and sentry to kite, slow and keep yourself alive while doing some some additional damage, and then using bola shot, elemental arrow and more spike traps to finish off enemies.
Go there :
Then click on the gem on the bottom of the page, right above the footer.
And you got your special build.
They did that to prove any build is viable. Expect dying often while trying to agree.
Works for other classes too.
Did that because I wanted a new WD build, and got almost the same I'm currently using,