PubMatic Senior Software Engineer interview questions

Very smooth interview process. HR reached over a call for a screening process. R1 - Technical with linear data structure based questions, Java basics, R2 - Low Level Design, R3 - High Level Design

I was interviewed for senior SWE role, the interviewer was also having same experience as mine but more on Spark and Data stuff and no backend, cloud. Contrary I was good at Backend, cloud. He asked me Leetcode style question, K- Anagrams, unfortunately I'd never seen this questions before and took extra time No question related to experience, cloud, backend, data engineering