ServiceNow Senior Applications Developer interview questions

First, A coding Question was sent over email, Post that 2 rounds on Day 1. After a week 2 more rounds and then again 1 more round as they weren't sure about me. HR was the worst part as she couldn't update me on the status and it's very bad experience as they were overwhelmed with the people attending the interviews and it's always a whole day dedicated to them for 2 rounds and I answered almost all coding questions but some System Design Questions were subjective, So, Don't know where It went wrong and didn't receive feedback from them as well on where they weren't sure about me. Be sure to have lot of time to contact HR about the status as no one will respond back and you have to call them to know about it. One round in particular was taken by Wannabe Google Engineer but couldn't get in so assumed ServiceNow is his/her own company and asked all bad questions where you will feel like it's just not worth going for the interview and waste time, I really felt like this must be the worst interview I've attended in my career. I don't think he/she was prepared to take the interview. The other interviewers were quite decent. But then again if you mug up all the LeetCode Easy/Medium Most Asked Questions, You're welcome at ServiceNow. I answered all of the attached questions but still Don't know what they were looking for. I applied for Backend position but they were always asking about whether I've done any front-end stuff.