(In this course, we visited large Internet companies such as Ali, Baidu, and JD.com, conducted in-depth exchanges with front-line development leaders, introduced them into our course, and summarized and extracted the first solution—— The means and methods used by first-line Internet companies to deal with large traffic and high concurrency. Through the study of this course, let everyone understand how first-line Internet companies solve the problem of large traffic and high concurrency? Thereby guiding their own work practice.)