Finding a translation solution for HubSpot is not as easy as it may seem. However, you're much safer with providers who eat their own dog food. Smartling is great but it's not the only option you have.
We're a HubSpot partner (check us out in the HS catalog here) and one of the main reasons for choosing this CMS was the approach to the multilingual aspect and website localization and the fact that we plan on expanding our own website into a few languages other than English. This way we've been able to build and test a HubSpot website translation process on ourselves even before we started.
Check outthis pageto learn more about our HubSpot translation integration.
This video also contains some more information about translation integrations, including HS, check it out: