I received an employee referral for Blackstone in late October and was asked to come in for an on-site interview. Of the three technical questions I was expected to answer, I was able to soar through one, made some errors on the second, and completely struggled with the third. However, the interviewer was a fantastic teacher and I was especially impressed by his patience and ability to help me through when I was struggling, and I eventually got the answer. However, I wasn't feeling too confident about the results of the interview because of where I struggled. Combine this with a lack of followup from Blackstone over the next week and I assumed I hadn't made the cut. Then came the end of November, exactly 30 days after my first interview, and I suddenly received an email from Blackstone notifying me that I'd been invited to an on-site Superday, which I was also informed was two days away. I was a bit annoyed that I didn't get a full 48 hours advance notice, but I came in for the interview. It was about 3-4 hours, with three back-to-back-to-back interviews (first a mix of technical and behavioral, then strictly technical, then a behavioral/description-based), followed by a keynote presentation about a project, probably to gauge what type of questions we'd ask after the presentation, and concluding with a very nice lunch with some of the developers. I most definitely messed up most on the last interview, fumbling my way through my behavioral answers (much to my own surprise), so I definitely recommend you don't underestimate the thought given to your answers when preparing. My technical I felt more confident in. I expected to hear back from them after about a week, but never did. I waited about three weeks before emailing the HR recruiter I had gone through to ask if my application was still under consideration, and about 20 minutes later received a hurried call from her informing me that I hadn't made the cut. I thought this aspect was especially disappointing, given that I had made it to superday I was at least expecting a proper rejection email in a timely fashion (and while we're at it, having more than 48 hours notice before finding out I had a superday), so overall I have to rate this experience as having left a sour taste in my mouth. The content of the interviews themselves were great though.