When I left university I worked as a colloid scientist in industry (for Unilever) but I eventually got bored by that and I left to run the IT department for a local company. Then I got bored again and left to work for what you'd call a start-up these days.
When I got to be 50 I decided I wanted time off so I retired, but the start-up still wanted me to maintain the systems I'd put in place. So now I spend the first couple of hours each day working for my old company then the rest of the day messing around on the Physics SE. That's what I mean by a part time computer nerd.