Much of the consumer developing happened in largish labs with large staffs and big, moderate to high volume machines.
Think hundreds to thousands of rolls per day.
After the film was developed, it would be printed using semi-automatic or automatic printers. The prints were made on roll paper, which was developed in a roll fed processor.
The semi-automatic machines had more operator involvement - much of my colour printing experience involved use of a Durst machine that was on the smaller side of things.
The professional labs were smaller, but their volumes were high, and their film processing machines were less likely to be roller transport and more likely to be reel and cage or dip and dunk.
A very large percentage of the labs were independent, but the Kodak (and later Fuji) big labs did high volumes.
Here is an interesting flickr post and thread about Mortifee Munshaw, a fairly high volume (and lower cost) lab in Vancouver. Note the job descriptions and the lists of remembered co-workers:
https://www.flickr.com/photos/bigsnit/4132930460/