I've worked with Siemens, and Rockwell Automation controllers(10+ years).
Not sure how many PLC techs or automation engineers frequent dev.to but ask me anything.
I've worked mainly in the oil, and gas industry for one of the biggest OEM worldwide. Now I work for another big OEM/operator in the land rigs area. As far as the automation type this is heavy equipment, so yeah lots of moving parts, hydraulics, pneumatics, tons of IO sensors. Full time job for OEM.
Before working in the oil and field, I've worked briefly in food manufacturing, and plastipack packaging. All, in all a little bit of everything conveyors, sorting, etc.
I also spent 4 years in the Navy as an Interior Comms Tech, in Norfolk, VA.
Note: If you want to learn about programming plc's, I suggest you install CodeSys it is free and IEC compliant with hundreds of manufacturers. In addition you can simulate programs without needing hardware. Also codesys support raspberry pi.
Edit 1: As per Blaine's comment.
Edit 2: Added CodeSys information.