In this chapter, we looked closely at how browsers work behind the scenes to render a web page. We delved into networking layers as well to understand the basic flow of network request/response. You learned about the critical rendering path and the importance of optimizing it. In the process, we uncovered the 500-milliseconds and 14-KB limit we have to ensure the delivery of critical resources to complete the initial application load. We looked at several different strategies to greatly optimize the critical rendering path. Towards the end of the chapter, we also touched upon strategies to deliver high performance with active application usage while dealing with massive amounts of bidirectional data transfers.
In the next chapter, we will look into profiling and analyzing application performance using some debugging tools.