If you're running a vanilla Django site with no esoteric libraries with special requirements (like numpy/scipy that need compilers etc. to get installed), this

If you're running a vanilla Django site with no esoteric libraries with special requirements (like numpy/scipy that need compilers etc. to get installed), this is definitely the correct way to go. But if you do have non-standard requirements that fall out of the rails of your PaaS, you need to consider other solutions.