I've worked for a Taiwan-based company for years. It's a somewhat multilingual society, but the default in workplaces is, of course, Mandarin, and English proficiency of the overall population is lower than you might expect (and than many would like; there's been a push for better English education in public schools lately).
In this company, at least, you would imagine somewhat inaccurately.
I speak English and three or four words of Mandarin. Their English proficiency ranges from equal to my Mandarin to almost idiomatic American English (a few having spent between a couple years and half or more of their lives working and/or studying in the US).
For live conversations, "English" technical terms are just a given, even for those who I can't even hold an minimal English conversation with. There are "translations" of things like "pointer", "file", "hard drive", etc.. They don't use them. Those most fluent in English engage in more significant code switching, with entire sentences or large sentence fragments in English.
I can sometimes extract significant meaning from conversations that are not otherwise in English because of this. They are frequently surprised by this, because they don't even think about it. These parts of English have simply been incorporated into a sort of programmer's dialect, it is part of their "native" language now.
Those who are most fluent in English, however, have told me they sometimes find it easier to have technical conversations entirely in English. I've heard two different reasons given for this, sometimes by the same person. One is the most obvious: This industry basically originated in English-speaking countries, so it's built on the assumption of English. The second is probably more locale-specific: Mandarin is apparently less precise and/or concise than English. One person described it as more "flowing" or "stream-of-consciousness", another as "based on feeling". Maybe not ideal for a field where precision is critical.
Documentation follows a similar pattern. The more comfortable they are in English, the more likely they are to use English, at least in part, in documentation. Commit messages, interestingly, are much more likely to be in English than Chinese.
Within code, APIs, and file formats, identifiers are almost invariably in English. Sometimes strange English, but English nonetheless. I imagine this would be less the case if we'd had UTF-8 source code 30 years ago, but it's where we are now. Filenames are also usually in English.
Comments are another mixed bag. Some developers whose English is very poor nonetheless comment exclusively in English, others use primarily Chinese. Again, the more fluent are likely to comment entirely in English. (This assumes the existence of comments at all, of course.)
Obviously when they specifically intend for me to read or deal with something, or are modifying code I wrote, everything is in English, but that's a fraction of what goes on in R&D.