I’m a system integrator, and though I don’t do it right now, I’d consider myself an expert in dairy. I could see someone specializing in chocolate similarly.
The reason people don’t know about these jobs is because they aren’t advertised very well. My MS in mechanical engineering barely touched on it and I sort of fell into it on accident by knowing someone in the industry.
Edit: thinking about it for a moment, I actually did some work for a European chocolate producer about a decade ago
It depends what you want to do. System integration is sort of the broad name for people in my field. Its a software stack sort of like how networking layers work. Controls->scada->MES->janky messaging connector->SAP with other random stuff sprinkled in. The Wikipedia article has an OK introduction to it.
If your interested take a controls class that actually uses Rockwell or Siemens PLCs, not the theoretical stuff. There is also open source stuff that runs on arduino or other controllers.
Or see if you like programming. Python is used for inductive automations Ignition SCADA and visual basic/C# is AVEVAs wonder ware. Their are others out there, these are the ones I’ve used.