Raindrop outsources some of their development to Ukraine. Perhaps, someone left `<html lang="ru">` somewhere. Many IDEs and editors use system language inside their HTML templates by default. I think, WebStorm does it, maybe some others.
In addition, many companies like Facebook offer localized versions of SDK downloads and Widget scripts. Thus, when a developer somewhere in China downloads the SDK and puts the <script> tags on their page, people from all over the world will see Facebook authentication dialog in Chinese.
In addition, many companies like Facebook offer localized versions of SDK downloads and Widget scripts. Thus, when a developer somewhere in China downloads the SDK and puts the <script> tags on their page, people from all over the world will see Facebook authentication dialog in Chinese.
Localization can be tricky.