We've done hundreds of them. We anticipate modules that might break, fix broken skins and containers, and write custom code where needed. Third party modules and skins may require extra billing, but we always quote first and provide alternative options when possible. When using core INNO modules and skins, upgrade issues are covered by our warranty.
We offer DNN upgrades on 3rd-Party servers as well as custom DNN skins and DNN module development.