It could be only one thing:
A software operations engineer on call.
I'm not an idea, but I stand in those shoes
While they don't develop the software, they are an important part of the process
Can't count the times that I've been used
Even the smallest problem in operations requires immense background knowledge, hence the operator is frequently pulled in to help
Sometimes I'm seen, sometimes I'm not
Just a fact of the corporate world - sometimes your work is appreciated, other times the people who keep things running are invisible
But when I die, I wont be forgot
"Hey, do you know how to do X? Jerry was always in charge of that, shame he was hit by a truck."
You hold of high authority, I bid your one command
Operations engineers are often considered the 'body' of the company, while taking commands from the 'brain' (architects, tech leads, etc.)
But of your money, I often demand
No one would want to do this s*** for free (except of course on evening, weekends, and holidays)
As night draws near, I sit and wait
For I'll be needed, when it's late.
The operations engineer on call bitterly waits through the evening for production breaks at 1 AM.