The darkroom has been replaced with Lightroom these days and many of today's photographers do not have the experience of processing their own prints the old fashioned way, much less anything larger than a common size. Here is a video from Norwegian photo assistant Oystein Gronvold which shows the process of producing a large 4x5 foot print in the darkroom.
The print in the video was of an image shot by photographer Dag Alveng. It is a 120x150cm silver print created from an 8x10 negative. Although the video is condensed into a very short 3 minutes the actual process can take upwards of 5 hours to complete. Unlike using Lightroom, if you mess something up there is no undo button, and the process has to be restarted from scratch.