I applied online for a backend software engineer position in Thailand. After about six weeks, I received an email from an Agoda recruiter scheduling two back-to-back interviews. I had to reschedule, and they were open to it.

I was not informed of the interview process. I completed two one-hour interviews with their engineers. The questions were easy LeetCode-style problems, as well as coding questions on implementing specific functions and creating unit test cases for certain functions. There were also general questions on other topics.

After the first round, I was invited to a second round with two SDMs at the time. This round focused more on software architecture and design.

I assumed there would be a third round, but I was called to be given an offer.

Overall, it was a positive experience, but the lack of communication regarding the process was somewhat negative.

How would you change the given code so that it is unit testable?