Stripe is a great place to work in some ways but judging from the writeup they had a ton of context switching preventing their productivity and the needs of the team didn’t align with what they did best. I’ve seen this feedback many times in many jobs.
I’ve been there myself! No doubt this person will find something exciting in no time.
Apropos of nothing as interviewers we do not put any weight on your submitting solutions after the window closes because we have to evaluate candidates consistently for business and legal reasons. We can’t give one person extra time because that’s not applying a consistent bar. Smaller companies may be more flexible but big tech won’t be. On the plus side big tech knows interviews are often a function of luck and setting and will generally always invite you to apply again without prejudice a few months later.
Being in a position to recover by getting bored and hacking on stuff you’re passionate about without pressure is something we’re really lucky to have, and I always try to do this between jobs.