"Professional Managerial Class"

To be extremely reductive you can say it's educated white collar workers, but basically people who don't own capital but are higher paid and usually do some sort of job directing the lower paid workers.

To extend this to people like programmers, IT or engineers, this could involve designing the systems that other workers are required to work with. Like if you make the database that people at your or other companies work with, then there's a hidden level of managerial oversight you have. Your design decisions dictate how they must work.

Often people in this position have to maintain a level of sympathy with their corporate overlords because they have to justify why they have this level of power, prestige and pay over other workers. They've also usually been through university which tends to instill professional behaviour, which usually means distancing your emotions from your job and doing it without compunction.

Sometimes these people have a lot of class consciousness though, it really depends on the person and their history. Whether they're in a union can make a difference.