Wolters Kluwer Software Developer interview questions

First, I cleared the first round of Coding . Questions were moderate level. Reasoning and aptitude questions were there. Total 4 sections were there. Coding question is Find the power of a large number and return the last digit . Input : 2^2 Output : 4 Input : 4^2 Output : 6

The first round of interview was scheduled by the HR. I joined the call 5 minutes before the scheduled time. None of the interviewers joined. I waited for 20 mins and called the HR lady twice to make sure it wasn't postponed but didn't got any response from her. I dropped off and emailed the HR to reschedule. It has been more than 2 weeks and neither has she called back or reverted back on my email. Completely unprofessional behavior and wasted my time.