Ran out of time on Perplexity's ToDo list problem

Ran out of time on Perplexity's ToDo list problem

Just wrapped up my Perplexity loop, phone screen plus 3 onsite rounds, rejected after the onsite so figured I'd write up what I saw for whoever's next.

Phone screen was the ToDo list for AI problem, four parts building on a TaskStatus/Task/ToDoList setup in Python. First two parts (add, get, update status) are straightforward, but part 2 also wants you tracking parent and child dependencies and cascading BLOCKED/READY/FAILED through the tree when something changes status. That's where DFS comes in and where I ran out of time, my cascade logic worked on the small cases but I never got to test it against anything bigger before time was up. The instructions themselves read like reading a novel, way more text per part than a typical LC problem.

Onsite had a system design round on mint.com style personal finance aggregation, and a separate infra round where they describe an overloaded system and want you to name the metrics you'd pull to debug it, felt like k8s trivia mixed with actual reasoning. Third round was coding again but I don't remember much of it at this point.

Python is required for the coding rounds, that tripped up at least one other person I talked to who does everything in Java normally. If you're prepping, get comfortable with generators too, seems to come up.