Can you describe a tough software development problem you encountered in your last job and discuss how you solved it?

"When creating an internal application to help our company's employees track their expenses, there was a bug in the program which impacted the rounding of percentages. After hours of examining the application and attempting to fix the problem, I was unable to identify the bug. I asked one of my peers to look at my code, and they quickly found the issue. This helped me realize that sometimes I'm too familiar with the code I write, and a fresh set of eyes can be helpful."