I did something similar. New strings would get Google Translate translations when we merged changes in. Then it would kick off a translation job through a human

I did something similar. New strings would get Google Translate translations when we merged changes in. Then it would kick off a translation job through a human translation service. We'd have to periodically poll that service to pull translations in. Then once we pushed to QA, our in-house teams could look at the app and tweak the translations. It worked most of the time, but the lack of context around what the strings were for did result in bad translations.