I enjoyed being able to shadow the different engineers to get a first-hand experience of what an engineer does within a firm.
What I wish was different
I wish I could have spent more time shadowing the engineers; they had a very tight schedule for when I was able to come in at times.
Advice
I would advise anyone going into this volunteer position to do some prior research about what the company he is shadowing does. It will make it easier to follow what the engineers do.