EMU mechanics belong to the vehicle system. Shanghai Bureau has Shanghai EMU, and Nanjing East Depot has this position. Responsible for all kinds of faults encountered in the operation of EMU (on-board operation), and usually take a few days off.
If you pass the interview, congratulations. You were hired after one year's probation, and nothing serious can be turned into a formal job.
Fresh graduates are all regular workers when they enter the railway bureau, so don't worry.
I hope I can help you, and you can ask me if you don't understand ~