I've done work in various industries over the years, but I got my start in the mining industry, because there is so much mining right here in my own backyard. My first big PLC project was a blending system for producing spec grade aggregate for manufacturing cultured marble countertops. I've also done numerous lime and cement kilning projects over the years.
Other industries that I've worked in include sawmills, paper mills, pigment plants, waste water treatment facilities, coal fired power generation plants and foundries. In the food industry, I've done software for ice cream and bread production. I've also made various program changes for existing control systems at Honda and Chrysler/Fiat automotive production facilities, although I've never been responsible for creating a new application in the automotive industry.
Back in the 80s, many industries routinely turned to outside contractors to handle their automation projects, but nowadays, it is far more common for manufacturers to have extensive in-house expertise. I doubt that I'd encounter opportunities in such a wide variety of industries had I started my career in automation today.
These days, I work with a relatively small company and the bulk of our work is in support of local lime kilning operations. I always enjoyed my work back during my heyday, but I don't miss all of the travel, now that I'm a grandfather nearing retirement.