A common path to such a career is to have deep expertise in some esoteric(or deprecated) tech stack. Cobol programmer comes to mind. You may only be asked to help once a month (or even once a year) but when they need you they really need you, and are willing to pay handsomely.
The question brings to mind this story (if anyone has a reference please provide).
A company hires a management consultant to assist with cost cutting. After spending time on-site observing the workflow, he has a meeting with a senior management and gives his recommendations. He mentions a guy who sits in his office seemingly doing nothing, and suggests they let him go. The manager says no, he's a critical member. About once a month we have a really complex problem that requires a creative solution, and he always provides one.
The question brings to mind this story (if anyone has a reference please provide).
A company hires a management consultant to assist with cost cutting. After spending time on-site observing the workflow, he has a meeting with a senior management and gives his recommendations. He mentions a guy who sits in his office seemingly doing nothing, and suggests they let him go. The manager says no, he's a critical member. About once a month we have a really complex problem that requires a creative solution, and he always provides one.