Answer 1

If you know how to create an app just like TikTok, you could earn millions of dollars. You expect to get that answer on SoloLearn? 🤣
You would need deep knowledge about distributed systems, data management, compression, security, machine learning, and probably a dozen other areas that can be challenging to implement.

If you look for a toy solution, maybe this can help (since you mentioned java in tag)
https://medium.com/@saravanastar/video-streaming-over-http-using-spring-boot-51e9830a3b8