(We often say that performance is always the first requirement. As a front-end engineer, no matter what framework you use, no matter what type of website or application development you are engaged in, as long as the project is used by users, performance optimization is always your concern. Usually, engineers can only summarize the performance optimization scheme after deeply understanding the front-end technical principle, which requires years of experience. Front end technology is changing with each passing day. In recent years, excellent performance optimization schemes emerge in endlessly. This course takes you to solve the problem of front-end performance optimization with very cutting-edge and professional solutions in today's industry. Whether it is to solve practical problems at work or improve your ability, this course can help you.)