I worked there for two years as an engineer for a multinational without speaking Japanese. The primary language of my team was english so the workdays were fine

I worked there for two years as an engineer for a multinational without speaking Japanese. The primary language of my team was english so the workdays were fine. I eventually was able to speak enough broken Japanese to order at restaurants, cafes, etc but anything beyond that was impossible for me. I know there are a few companies (Google, Facebook) that are hiring engineers in Japan where English is the primary language used. I have heard that there are also some native Japanese companies, like Mercari, where a significant amount of English is used as well. I found that not speaking Japanese was not that big of a deal especially if you live in central Tokyo or one of the suburbs that have a lot of expats. Most businesses that you would likely frequent will have english menus or speak enough broken english to get by. I had a few health problems while I was out there and there are several clinics that have native english support. The thing I found the most difficult about Japan is making Japanese friends. You will always be an outsider and in general Japanese folks just have different expectations when it comes to "work" friends vs "real" friends. You might think you're super close to a colleague from work but in reality you're a total stranger. It's not uncommon to not even know if someone is married or not. On the other hand if you're okay with having mostly expat friends, the community is very welcoming.