The popularity of computers in China is only two decades, so the oldest group of programmers are only in their forties. Because of the expansion and popularization of enrollment, the number of programmers in their 40s is only a few tenths of the number of young people nowadays, and most of them are managerial (a few with poor ability and eloquence become grassroots or even eliminated). If it is front-end, APP, big data AI and other emerging fields, there are very few people over 40. From a technical and physical point of view, programmers have no problem retiring at 55 or 60. The fighting force will not be worse than that of a 30 year old. Learning new technologies may be a little slower, but experience makes up for overall efficiency. Generally speaking, slightly outdated technology development is the best value for money. Studies show that programmers peak around age 50. Refer to the chart below. I've met the top brass of some foreign IT companies, and almost all of them are bearded old men and middle managers, and all of them are predominantly in their 40s and 50s. In some traditional companies, the main programmers are around forty. The Internet category is younger, but still larger than at home.