Skillz's interview process is pretty brutal, especially since this an early startup (and not Google...). I would think twice how serious you are before starting their interview process.
First round call with HR is a cake walk. Be prepared to talk about compensation, including base, equity and total compensation. Saying you're "flexible" will not suffice, they will want a specific number. I think they're not willing to go above 110K for total compensation, so keep that in mind. And make sure to have played at least a few of their games ahead of time. I have to admit while they are too obsessed with their product, that's better than other startups I've interviewed with where they talk more about the position and culture but brush their product aside.
Next step is a 4 hour take home assessment and a HackerRank test. You have to schedule this ahead of time and the weekend is fair game. The assessment is about an A/B test, and can be done in excel. The data is presented in excel and there's like 200 rows and maybe 15 columns. They do give you way too many variables for you to go through all of them in 4 hours. I wish I had known this before, because I've never looked at A/B data before, so I wasn't sure the best way to describe if it was successful or not.
The HackerRant test is, honestly, really not fair and makes me frustrated just thinking about it. It's 15 minutes for 15 questions that are SAT math questions. I tried spending an hour or so preparing beforehand, but even then, it's literally impossible to get through half of these questions in 15 minutes. I can't say that I've ever come across any of the questions in my line of work and doubt I would if I joined Skillz.
I honestly thought I would not make it past this round after taking those. But after a few days, HR got back to me to schedule a 2.5 hour time slot for Zoom interviews.
There were 3 interviews. The first one was a 45 minute A/B cast study and the second one was a 45 minute user acquisition case study. I had prepared for a more consulting case study, but they show the case in a Google sheet. Most questions are theoretical and no responses required any specific numbers. The case studies were also related to their product, so it's important that you understand their platform beforehand. The biggest tip I can offer is that one of Skillz's main goal is to get more deposits into their platform.
The final interview was a 30 minute interview with a hiring manager that was all behavioral questions and very casual. I thought the interviews were pretty nice and actually wanted you to succeed and we're girly genuinely interested in your responses.
A few days after this, I got a generic rejection email from them. I had mixed feeling because I felt I did poorly on the take home assignments but performed well during the interviews. So I have a feeling, similar to another Glassdoor reviewer, that Skillz progressed me to the Zoom interviews to only reject me based on my take home assignments.