How do engineers make cyber networks safer?

As I have worked through the years for many high end companies as an engineer, I have seen many methods to keeping cyber networks safer. When it comes to in house systems the companies will set up a network that will be in house only and keep most of the systems offline to keep from the chance of cyber attacks. When dealing with the multi step authentication many companies will create many steps and level privileges to users as well. With access to remote work on a system, most of the time technicians get only minimal access and will have to access most of their information that is given to them by their parent company, leaving all in house information for engineers only. This creates a barrier for many operations to take place without the spread of information. The varying degrees of clearance levels for information creates a deep web of priorities, leaving a whole department of cyber security associates on full alert when it comes to violations. When given access to company computers the cyber security groups will secretly do tests on the security precautions of the employees given access. Over my time in the companies I’ve worked for there have been many attempts to test my vigilance and verify use of the computers is not violated. Prefabricated emails will be sent out randomly and will test what is done in case of a phishing email for example. Not only will emails be set up to test you but internet access will be monitored as well, sometimes even limiting the use of the internet especially when connected to a VPN. As the technology advances there will be engineers on the scene to verify use, find bugs and protect the systems that are in constant danger from attack, creating an endless amount of firewalls, network paths and parameters for cyber awareness.