Arcesium Engineering Lead interview questions

First there was hackerrank round,not related to ds, All rounds were online due to covid. Some api needed to be called.Then there was technical screening, in which interviewer had to cover all basic topics, including ds, design,jvm .Data structures was not that difficult.Then 3 rounds of interview were there, first one was from resume and some basic ETL design question. Second one was foccused on database design for ecommerce website, in third one , they asked to design git class which offers commit,log ,status and branch operations.I had fairly good interviews.But I don't know what went wrong.They told me , they would be giving results/next step in 2 days and after 3 days got rejection mail , to which one even can't ask feedback about what went wrong.