Is there any way to handle localization as an indie-dev?

I have my product landing page in English and I want to translate it into several different languages. Translating all pages just once is a lot of work, but doable.

The problem: how to keep all the locales updated and in sync with the main version? If I change something in my English landing page, I want it to be reflected on all landing pages. I could do this manually, but making any small change will then take a lot of time.

Does anyone use any software automation translation or service that handles page internalization (e.g. you provide the landing page in English and they automatically maintain the Spanish and French versions)?