By default in official Arduino documentation no any information about WatchDog timer. WatchDog timer (WDT in short) – is a hardware external timer that reset the microcontroller if the main program crashed or go to the infinite loop or etc error action.
Sometimes in javascript need to use sleep. It’s not a good practice (maybe good way – change some code?), but if you found this article you know, how it use and need only construction)
Nginx – is a popular web server. One of the way of using it – is a reverse proxy. And in this article demonstrate, how to use it as the reverse proxy for WSS (WebSocket Secure).