What do border checkpoints do?

That's a port of the public security frontier troops, that is, border inspection, which checks the entry and exit situation. Usually, it has a port.

generally, you don't recruit from outside, unless you are a college student and you can get the job.

Introduction to Frontier Inspection Station:

Shanghai Entry-Exit Frontier Inspection Station (hereinafter referred to as "Shanghai Frontier Inspection Station") was formally established on July 1, 1998. It is under the vertical leadership of the Ministry of Public Security and is organized at the deputy department level, belonging to the compilation sequence of the people's police.

At present, there are eight entry-exit frontier inspection stations at the official level under the jurisdiction of Shanghai, Hongqiao, Jinshan, Wusong, Waigaoqiao, Pudong, Railway and Yangshan, with nearly 1,6 policemen and employees. On behalf of the state, Shanghai Frontier Inspection Station conducts entry-exit frontier inspection for entry-exit personnel, their luggage, means of transport and the goods they carry at all ports open to the outside world in Shanghai. The service areas include Pudong International Airport, Hongqiao International Airport, Shanghai Railway Station and Shanghai Port.

In recent years, in the face of the situation that the border inspection task has continuously jumped by a large margin, all police officers in Shanghai Border Inspection Station have insisted on establishing police for the public and enforcing the law for the people, fully developed the spirit of loyalty, dedication, dedication and pursuit of Excellence, effectively maintained the safety and smoothness of Shanghai's entry and exit ports and made positive contributions to serving Shanghai's economic and social development.