Yeah, it can’t be soloed at all or that easy. To this day, it’s still a pain. Blizzard dropped the ball hard by making that casting time on the hack unbearable. A simple fix seeing as it’s three xpacks old content and shouldn’t be able to 1 shot us at all is to just make the hacking bit faster. Like, press the button and win type of fast. But they won’t do that cause the devs are too lazy to take one person and less than an hour to fix that programming. One day. Maybe. One day.
It still works to run back to rustbolt out of range and then go back and hack the pylon.
So glad I found this post. 
If I recall you need to be quick, as the boss will try to path to you and despawns if it clips through any of the scrapyard walls. So you need to jump down and book it back to the scrapyard running directly for the gate.