PayPal Software Engineer interview experience

The conversation started with questions that were more about fundamentals than pure algorithms, and then I was given a coding assignment where I had to implement an array-based structure supporting O(1) operations for something like a set-all behavior.

After that main piece, the interviewer also asked about multithreading related to that set-all array implementation. That shift—from algorithmic thinking to concurrency details—was what threw me off most, because it wasn’t something I could just treat as “another LeetCode problem.” I had to think about correctness in a more system-like way.

I