Its Army Reserves. Yes, I am already locked in for a pension. I am not a civilian. I am completely interchangeable with full time military, evidenced by my 5 military deployments.

How does a person get such a job? They join the military.

When I joined cyber wasn't a thing, because I am old. I joined the first cyber organization shortly after it formed and was a member for about a decade. I was promoted out of that organization and shortly thereafter a formal cyber organization was created, not just a few units. By that point I had become an officer doing more generic systems integration and physical communication infrastructure things.

The biggest difference between the military side versus the corporate developer side is that military tends to run towards problems. The goal is have everything working so that you reach steady state and don't have to do high visibility work. High visibility is bad, because it suggests you are failing something important. Corporate developers, on the other hand, tend to be either trend chasers that want high visibility yet low effort work until things fall apart and then they run away or are long term employees that want boring steady constant employment.