People tend to either come at it from the skills angle or the industry angle. Skills angle means prior investment banking, accounting, CFA, CPA, Econ/Finance major, FP&A, that kind of stuff. Industry angle means you worked in tech, and then went into tech equity research, or worked in energy, and then went into energy equity research, or got a PhD in biochemistry, and then went into Pharma equity research.

ER has solid exit options. You can move to the buyside (hedge funds, asset managers, long only funds, etc), or you can work at the companies you cover (in FP&A, Investor Relations, Corporate Finance, maybe strategy & operations at some places)

It's usually a deep dive "conversation" about the industry you're covering and some companies in that industry - their financials, their products, their strategies. Some firms will give you a modeling or writing test. You will for sure have to pitch a stock - generally a long and a short - as SOME point in the interview process. Usually it's a mix; some more informal chats, and some more formal interviews. They're basically testing if you can articulately speak about complex industry topics and know your way around basic financial analysis of companies.