The mobile technology has become more and more mature, and it has evolved from a ridiculous situation in 2012 to now. For the Chinese engineers, we are more concerned about such a few points, hotfix, performance, development efficiency, App size and data-driven products. These aspects have already had very good solutions at present, but also emerged some excellent framework like RxJava, CanaryLeak. This topic is very big, and also out of this book scope.

      By the immense prosperity of App technology, I recall my first job in 2004, the IT industry was transitioning from CS to BS. CS is a Client/Server architecture. For example, if you install a client of Lianzhong game center on Windows system, you can get the client of Texas Hold'em poker. After the technology of the Internet grew up, you start to move the original system into the website. This is BS, the full name is Browser/Server architecture.

      To compare with CS, BS was a thin client, many features were not supported by BS. It came up with the concept of a SmartClient, which is a smart client. Outlook is a good sample. You can read and write E-mail offline without network, when the network is available, it send a written e-mail automatically.

      Then, Flash was become hot. This was a tool for three webmasters originally, but it became the originator of the web-rich client. Based on Flash, there will be Flex, and now some companies are adopted Flex. At this time, Microsoft also came in and created a Silverlight, which is also similar to Flash on the web. At the same time, JavaScript is also working hard and gradually replacing the former and becoming the final winner of the rich client. A book was very popular at that time, it is called "JavaScript Design Patterns."

      JavaScript was only used to do web visual effects in 2004. Ten years later, JavaScript has experienced with ajax, jQuery, ECMAScript from 1 to 6, Webpack packaging, and so on. The frameworks of Angular, React, Vue have become extremely powerful and have been packaged due to javascript as a "object-oriented" language.

      Compared with web technology, the App is also taking the same development path. First, it mute for a few years. Many of the technologies on the website are moved to the App, just like what we do today. The next stage is the transition from CS to BS. The Hybird technology is the above-mentioned BS, but there are many defects, especially the bad performance of Web browser, then there are React Native, HTML 5 is also slow, but you can translate HTML 5 into Native code . It is not clear for me to make such kind of progress, but the future is very clear. Android and iOS technology will not die; on the other hand, HTML 5 will become the main method of App development in following years.