This advice may not work for everyone but it worked for me so I'm posting it here. (also i main the medic so this is from a medics perspective)

A couple things you may need.

1.resurrection coins (At minimum 10)

2.A friend that knows how to not get themselves killed

3.The best weapon in your inventory

4.A disposable team that can get you to the boss

How to do it

When the boss spawns you need to get it to chase someone around one of the generators while you/(the rest of your team if they are alive) shoot at it from behind and you need to do it as quickly as possible before other cyborgs spawn in and if they spawn in try to kill them but if you die that's what the resurrection coins are for.