First step is a lottery which has been held at irregular intervals approximating every two years and applicants' names put on a list. There have been separate lotteries for bus operator, motorperson, customer service (on the ground) rep, and a few other position. The lotteries have been known to go into over 20,000 names.
The T then draws names a few at a time from the lottery in order as needed and as months go by. If someone has taken a different job somewhere else then his/her name is passed over. I think the motorperson lotteries (rapid transit and light rail) took about 5,000 names each before the lists were discarded and new lotteries held.
Then there are background checks, health exams, classroom training, on the road training, etc. A person might be disqualified at any stage along the way, if not then s/he is offered the job. Shifts and routes are picked by seniority 4 times a year. It is common for new hires to work split shifts i.e. morning rush and afternoon rush.
Have you taken the training program at a trolley museum and driven cars there? (Not just a one hour session.) This will give you an abbreviated idea of what the training would be like for the T or other city transit system.
Unfortunately disputes can get political. There have been a few instances where one of two or one of three persons had to be found at fault for an accident or a mishap and the final decision appeared to involve personal favoritism.
Build something. Anything.