Interviews for the 1:1 phone interview and HackerRank questions are the same, you can find various examples here of what they ask so I won't focus on that. You also get to bring your own laptop and use your own environment, which is extremely helpful because it's your own laptop and most likely you are very comfortable coding on it. I would say that I used Python 3, but for the bug squashing/request question, they had code for Python 2.. I mean it's 2019, so Python 3 should be a standard but apparently not?
I will focus on the onsite interview, which was 4 phases:
1. Solve a question in a language of your choice.
2. Bug squashing session.
3. One-on-one with an engineering manager.
4. Using APIs to send requests and work with JSON.
Phase 1 was fairly easy, there were 2 developers and they asked you a question and you code it out. I started working on the whiteboard but they said they'd want to see me code it out. solved it with a few minutes to spare.
Phase 2 was actualyl very difficult. I spent 20 minutes trying to even download from github and get everything set up because my laptop had no internet connection, and they brought me a macbook which I was not familiar with at all. Definitely recommend practicing with a Macbook (using the terminal for downloading, unzipping files, moving files) if you don't know how.
Phase 3, the engineering manager seemed very uninterested in me. I swear he was doing work or talking to other people in the meantime as his focus would switch the laptop quite often.
Phase 4, this was fun but my inexperience with requests and JSON definitely bit me on this one.
Had a lunch session after, and was denied I think a week after. Didn't even call for the denial, just sent an email, which is very professional, thanks Stripe!
Definitely recommend looking at the Glassdoor questions for help, because they really like using the same questions for all of their interviews.