What is the best way to work as a team on a UE4 Project?

I’m just wondering how working on a single project with a team is done within UE4.

I used Hero Engine in the past and it is amazing to work with as a team. One person can be adding assets, one changing code and one changing the terrain all at the same time. Its almost like an MMO of building a game. As a team spread out over the world it was great to log in and see people still working and finishing off their bit. Obviously it was based on servers not like UE4.

So how do you work within UE4 as a team?

Surely its not a matter of 20 programmers building the code, 10 sounds guys and 40 modellers building everything then giving to one guy/girl to put it all together.

Its just me at the moment, but as things grow would my current way of working have to be changed so much it would be easier to start again. If so I would rather have things in place now.

Thanks for any good input on this.