Analyst jobs are extremely competitive to land. It's an intensive interview process, and the vast majority of analysts do an internship first and are then hired on full time for the following year. As you might imagine, the job pays very well. Market rate at a bulge bracket firm for a first year analyst is $10k signing bonus, $70k base salary, and anywhere from $0 to ~$85k in bonus, though typically bonus is in the $55k - $75k range, depending on individual, group, and bank performance. As a second year, base and expected bonus each receive a $10k bump. Plus dinner is paid for every night, and lunches as well on weekends, which adds up to about another $10k. Most banks have a two year analyst program. A small percentage of analysts stay for a third year if offered (maybe 10%), and maybe 50-75% of those continue on to become associates, which puts them on track to eventually become a senior banker. Most associates were never analysts, but were instead hired in after doing an MBA.
After putting in the time as an analyst, a host of other opportunities await. Those with bulge bracket investment banking experience get all sorts of attention from recruiters. Many go on to work in private equity or for a hedge fund, both of which tend to pay significantly more than banking but with much more sane hours and a far better quality of life. Others do things like biz dev or take other misc finance roles. A very select few decide to go the startup route (eg this guy).
The combination of perceived prestige, high pay, and quality exit opportunities draw legions of juniors and seniors to apply. Senior bankers know that the role is in extremely high demand, and therefore they tend to be very tough on their analysts. If one analyst burns out, there are hundreds more frantically trying to network their way in to take their place.
There's a very clear divide between what a senior banker does and what a junior banker does. Senior bankers are glorified sales people. Their job is to maintain relationships (and develop new ones) with clients so that when the client decides to do a deal (any sort of M&A, financing, or restructuring), they'll hire the bank that employs said senior banker to execute/advise on the transaction. A junior banker's job is to do anything and everything that senior bankers tell them to do.
Junior bankers have very little control over their own lives. They're staffed on many projects at once (at one point I had 12 different projects I was juggling), and usually have minimal say on what projects they're assigned. These projects are generally all with different sets of people. Each senior banker tends to have a sub-industry and group of clients they cover, but junior bankers get shuffled around to work on any project that needs staffing. This staffing is determined by a "staffer" (usually a semi-senior banker), which is entirely discretion based. They try to make an effort to make the distribution of work equitable, but they have their job to do outside of being a staffer, and being a good staffer doesn't advance their career in the slightest, so they're not incentivized to really get this right. The work generally goes to the analyst that looks/seems the least busy.
I can't begin to describe how fucked up of a dynamic this creates. Insidious, underhanded politics. Analysts essentially forced to stay at the office until everyone above them has left the office regardless of whether or not they have anything to do. If you leave before the staffer leaves, you're guaranteed to get hit with the next staffing. If you leave before everyone above your level has left, they'll be bitching the next day about how they're working so hard even the analysts are leaving before them. Analysts subtly dropping hints to senior bankers about how much harder they're working than the other analysts, both in an effort to get staffing diverted away from themselves and because analysts all get ranked against each other at the end of the year, which determines their bonus. Analysts are ranked on a bell curve against each other, and bonus payouts among them are a zero-sum game. Recruiters and interviewers will ask you point-blank what your ranking and compensation was.
Analysts carry a blackberry with them at all times, and a staffing can blow up their next two weeks literally at any moment. You live in constant fear that that little red light blinking on your blackberry isn't another staffing or fire drill (ie "emergency" work that needs to be done immediately). You can't plan anything. Being too slow to respond to emails, including at midnight on weekends, is grounds for getting sat down for a stern conversation in a conference room. My blackberry was never more than 20 ft away from me for two solid years.
My average day was about 9:30am - 12:30am on weekdays, and about noon to 6pm on weekends. I didn't have my first day off, including weekends, until 4 months into the job. Sometimes it was as light as 50 hours per week, and sometimes as bad as 110+. Some of the time you actually have so much work to do that you're eating every meal at your desk and working solid the entire time, especially if you're working on a live deal, but a lot of the time you're just waiting around for other people to get back to you. They give you some work to do on a document or presentation, you spend a few hours doing it and get it back to them, and then you wait for them to get it back to you for another round of edits. You'll usually be doing this with 4 or 5 projects at a time, all with varying levels of complexity and urgency. This is one good part about the job. During the "day shift", life usually isn't so bad. A lot of times you can get away with long lunches and frequent starbucks runs without anyone really noticing. But then after a fairly leisurely day, come around 5pm or so, the "night shift" starts. You'll get edits to do for all of your projects at once and occasionally end up pulling an all nighter, even when the majority of the work you're doing involves formatting charts, transcribing pages of handwritten notes, and various other trivial, mind-numbing tasks.
You'd be amazed at how much effort we'd be asked to expend on some task relative to the benefit that that task could possibly hope to provide. Like put together this 10 page weekly update for every company in X industry, including what research analysts said about them that week, what the media has said about them, individual product sales, graphs of their stock price movements and their valuation multiples, etc. All painfully slow, manual work. There were 40-50 companies in this industry. For an update that was sent to a single client. Unsolicited. When the CFO hated the senior banker who ordered the update and would never do a deal with him in his life. Doing mind-numbing work is one thing, but spending hours and hours doing it when you know it's all for nothing is an indescribable feeling. I wanted to bash my head in with a stapler. It took me THREE MONTHS to finally convince the staffer to tell the senior banker it wasn't going to happen anymore. All sorts of absurd shit like this was thrust upon us in the name of potentially winning business.
I could keep going and probably fill several volumes about how horrible of an experience it was, but I'll stop there. The best day of my life to date was the day I turned in my blackberry and walked out of the building for the last time. I don't think that the people I worked with were inherently evil or anything like that. All else equal, they'd be senstive to our well being. But at the end of the day, we were just another class of indentured servants, like the many classes they'd seen before us and the many they'd see after.
When I would describe my life to friends and people I'd meet that weren't a part of the finance world, they would literally think I was making things up. The idea that someone would be willing to subject themselves to such insanity, or more accurately that an employer would demand it, wasn't part of their world view. I assure you, it was really that bad. I'm a pretty stable person, but there were a couple times where I came very close to coming unglued. Somehow we managed to convince ourselves it was all worth it. The jury's still out on that one.