So the Army doesn’t have Computer Engineers on Active Duty, but rather uses civil servants for this. In the Army, Engineering generally really refers to combat engineering.
The DAF (USAF/USSF), uniquely, does have engineers in uniform, but whether you count them as “real engineers” is a matter of opinion. Engineers are part of the DAF’s acquisition community, responsible for managing large and small government programs to design/build/maintain/procure just about everything in the arsenal and basically any other materiel needed for the service to function. This requires a large number of program/project managers to oversee contractors. Engineers generally serve in this role for technical systems in the inventory, rather than doing the engineering work themselves. Daily life involves meetings with contractors, planning/overseeing test events, briefing stakeholders on progress and risks, etc.
In CERTAIN assignments, this can be quite technical in that the officer needs to leverage a depth of technical expertise to do those above tasks, but for many, if not most assignments, civil servants and SETA contractors, fill the technical roles in a program management office, and the officer may only leverage their technical expertise in a much broader sense. Not saying it’s a bad job, but it’s definitely not what most people envision when they join the military in lieu of perusing a civilian career. How you feel about that is obviously a matter of opinion.
As for the minutiae you asked about, those things largely depend on assignment, but it’s generally a 9-5 style job and PT may or may not be a scheduled mandatory event before/after work, versus letting you do that when you want, based off of your own meeting schedule. There are assignments with more unusual schedules, but those are the exceptions.
