I applied online and received a coding challenge after approximately three months. They provided a 30-day window to complete it.

I anticipated it would be difficult, as most questions would likely cover operating systems (OS), concurrency, and algorithms. I had not taken any OS classes at university.

Therefore, I spent nearly 30 days preparing for the challenge before deciding to attempt it. They allocated 60 minutes to answer seven questions, which included multiple-choice, fill-in-the-blank, and three coding questions.

It was a difficult challenge for those who haven't taken OS classes, as many questions focused on OS knowledge, with one coding question specifically about acquiring and releasing locks. Four days after the coding challenge, I received the rejection email I had expected.

For those who will be taking this coding challenge and have not taken an OS class, I suggest talking to someone knowledgeable about OS, specifically regarding mutual exclusion and locks.

Coding Question:

Given a string, your task is to count how many palindromic substrings are in this string.