Reached out by a recruiter, I had a first phone call where she explained the role and roughly the work they were doing. I got the impression that she was reading the same job spec again and again in auto-mode. I was a bit disappointed when she said to me that "we have many candidates for this role, so unfortunately you won't receive any feedback in case the phone interview doesn't go well." OK, I said. Overall, the technical phone screen was easy. The engineer was nice and made me comfortable during the 50-minute interview on CoderPad. As usual with these companies, it's a gamble. Even if you provide the right solution and explain it, if they don't like it, they will simply reject you. This is how it works in companies where you have hundreds of candidates for every role opened.

Explain how you would check if a string is a palindrome, considering also time complexity for very long strings.