Pros
Could listen to a podcast. Couldn't take work home with me. Mostly left to my own devices. Line manager had previously done our job so at least knew what we were doing. Generally low stress. People were generally chill.
Cons
Comically underpaid at the time for a graduate role. We were technically not allowed to have phones in the cleanroom, but also expected to take pictures to describe parts that weren't working, etc. Stand-ups requiring leaving the cleanroom twice a day for no reason (we already had headsets for Teams calls!). Lean philosophy means we'll all run out of gloves, laser lids and then lasers, and the lowest rungs on the ladder will have to make up the lost time when they come back in. Suggested improvements are met with shrugs when you're a mere cleanroom lackey. Good luck getting promoted; if you're too good to lose in the cleanroom, they might not.