If you know at least a little bit of Russian, you must know such conversational formulas used to say goodbye as до свидания, до скорого, прощай(те) and пока. The etymology of the last one (пока) is not very clear -- it literally means for now, or still. It appeared at the beginning of the XX century, and it is most likely that it was derived from пока до свидания and пока прощайте (goodbye for now/for the time being). It was shortened to just пока and now it is officially accepted as an informal goodbye and taught to foreigners among other conversational formulas.
The reason that I'm telling you this is that I've noticed another way to say goodbye becoming widespread: now you can hear давай, пока or давай, до встречи or just давай used at the end of the conversation. Давай usually means let us, come on, let me and used with пока, до свидания, до встречи literally means [let us say] goodbye. And again, same thing as with пока: a word that has literally nothing to do with greetings or saying goodbye becomes to be used independently in its new meaning. It has been used for (I guess?) one or two decades, but still hasn’t been accepted as a language norm. But judging by how widely it is used I think that in 5-10 years it will be accepted by linguists as a new conversational formula and added to dictionaries and to Russian language textbooks.
I don't know whether you should use it to speak with Russians, but now you won't be surprised to hear it :)
P. S. And there is a meme давай до свидания, google it if curious
