This is for players that like to farm lot of EXP for soldier class only.
Guide to Farm EXP at Marketplace
This will explain how to farm EXP with soldier class only
I tested this on Easy mode so I can’t say if other modes works but this could work better with at least two maxed out armoured soldiers to swap if their armour need to regenerate)
In order to start, you will need to find optional location called “Supermarket”.
I had 4 people doing all the looting (Two medics and two engineers) while two soldiers with maxed out armour and one of them use a katana (Sword) to fight off any hordes on their own.
After all the looting, retreat your looters and fall back to this tight hallway where only one infected can enter at a time. (Surprisingly, they follow COVID distance to give your soldiers a break between each infected)
As you can see, most of infected is stuck at the entrance while few others are getting slaughtered by my soldier with katana.
I also trusted this progress to the point where I actually left my PC to eat my dinner so this is a good way to gain EXP without too much of a risk.
I can’t remember how long this takes but I will guess it took me an hour or more to be this far (Remember that Easy mode give you more EXP than Normal and Hard modes so keep that in mind).