This is the case with the iOS market, which has been declining since the end of 20 15. The main reason is that the popularity of iOS in previous years led to a large number of junior iOS development engineers trained by training institutions to go to the market in a short time, which caused employment pressure. But more importantly, it also has a lot to do with the development of Internet policy. People who pay a little attention to the internet market may know something about this situation. Since the second half of 20 15, a large number of small and medium-sized internet enterprises have declared bankruptcy. Many developers have also lost a lot of jobs. Therefore, for iOS development engineers, those who have jobs are afraid to quit easily, while those who have not found jobs either change careers or are still waiting hard, even a small internship opportunity will not give up easily. You can start with java. As an evergreen tree of programming, its talent demand has always been in the market.