Personally, I wouldn't trust Google or similar automated translators for the job. Since I only speak English, I don't have a way to verify whether the translations are correct and make sense in its context.
I've been considering translation services from Fiverr, but I've never used any services from them and it, too, has the same problem — I have no way to verify whether the translation is okay.
Has anyone translated their app/website into a different language? What's the approach that you used?
From a tech perspective we keep all this content on a very large and very complex Google Sheets file. We have an Apps Script function parse that file out into a bunch of json files that then go into our app structure. This works rather well and I would recommend it.
Initially I was translating "by hand", but this was very tedious. I thought that I could ensure a higher level of quality but I was only wasting time. Now I let the Google Translate do a first translation and I then make corrections to that instead. It's easier to hire/ask someone to correct an existing poor translation than to translate.
The cool thing is that we set up the Google Sheets so that our 'translators' can only access/edit their own language. A lot of the time the google translate works fine so they leave it as is. But if they make a correction they replace it with their own and highlight it. When we make changes to the content, we override that correction. We ask them to take a look every now and then. Because what they did before is highlighted, they only have to focus on the bits that are new.
Our translations are double checked... by other translators. You ask the AI to do the tedious bit, you pay someone to make corrections and then you ask someone to double-check.