Some of the people are hired into the program right out of college for two years. Most of these people are told that they should look for work elsewhere at the end.

(Other people are just hired and are not in the program.)

It's very competitive, so people work hard to try to make the cut.

In the US, if you make that cut, you have a chance to get promoted to Vice President, then Managing Director, then Partner.

The pay varies depending on your performance and the financial results of your part of the company and the company as a whole that year. Some people think a Managing Director can make about $1M per year, and a Partner can make about $5M per year. But no one really knows, and there are a lot of variables. I saw a NYT article that claimed that one particular Partner earned over $50M in one particular year.

I think when people right out of college are working all those hours, they are fighting for a chance to some day become Partner.