Those are "девелоперское окружение" (or even "девелоперский энвайормент" - pronounced usually closer to "энвайромент" however), or just simple "дев", "тестинг" or (very rarely and in official documentation) "тестовое окружение", "стейджинг", "препродакшн" or "препрод" and, finally, "продакшен", or just "прод".
Whether we like it or not, huge portion of dev-related terminology is used as is in English - and therefore became a part of Russian vocabulary just like the words "танк", "гаубица" or "телеграф" did it before. However every time one need to check. For instance, branches in version control are called interchangeably "бранч" and "ветка", for DB connections one can hear both "подключение" and "коннекшен". Or, for example, the most widely adopted pronunciation for ssh is "эс-эс-аш", not "эс-эс-эйч".