What is 'Curse of 35', which is impacting employees aged above 35 in China?

Employees in China are facing job insecurity due to 'Curse of 35', a widespread belief that companies don't prefer to work with them once they turn 35, reported New York Times. Many companies in China, including the government, have capped hiring age for several positions at 35. This has led to young people delaying marriage, having children and buying houses.