Doormen (porteiros) are omnipresent in urban Brazil. Everyone and their momma has one. I liken it to how some people like to close the door to their bedroom at night because they feel safer. Doormen are kind of like that. Depending on your place of residence, your doorman might be suited up or dressed down. Where I live, one of the porteiros is also a handyman (and in case they aren’t, they surely know someone who is).
As of 3 years ago, there were 414,000 porteiros in Brazil and June 9th has even been declared Doorman Day. Two side notes, I’ve never seen a doorwoman and I’m not sure if not hiring a woman for the job is illegal in Brazil. Also, I’ve never seen an armed doorman.
Generally, doormen are called security guards in the States and having one (or many) usually means you live in a rich area/place. One needs a Guard Card to apply for such a job and being armed requires further training and licensing. Depending on where one lives, the guards might ‘moonlight’ as concierges as well.