Please do not believe any of the positive reviews. AlphaSights is truly a terrible place to work.
First off, the work is absolutely miserable and borderline unethical. All you do is harass professionals all day through LinkedIn, email, calls, and texts for them to take a 1 hour call with your client, where a lot of the time they're looking for nearly confidential info. You are pushed and rewarded to disrespect experts' time, confidentiality boundaries and compensation; it's so incredibly unprofessional and would not be tolerated at any respectable workplace. You learn zero hard skills - all you do is search LinkedIn, send template emails, cold call experts, and write vague profiles on their experience for the client. This job is basically sales and recruiting but worse.
If that doesn't sound bad enough, you are micromanaged by a manager that is 2 years older than you and has zero experience outside of AS. You'll be forced to talk about your mundane tasks 3 times a day and announce anytime you'll be off the desk for 5 minutes. The managers will always ask for your feedback and say that it's a "feedback-oriented culture" but will also put you down for any negative feedback you give.
Also, the compensation and performance metrics are so incredibly unfair. It's all reliant on the types of projects you get, experts you have to work with, and level of engagement from the client. You'll be reprimanded on a weekly basis about your performance, even though the vast majority of it is out of your control.