Deutsche Bank Automation Testing Engineer interview questions

Below were the questions asked - [ ] Write code to read data from excel - [x] Return type of findElements - [x] Return type get window handles - [x] Write code for the number is palindrome - [x] Write code to take screenshot - [x] Write code to reverse a string - [ ] Write testng xml for parallel execution - [x] How to run headlsss - [x] How to find if element is present or not - [x] Constructor - [x] Write how to retrieve json response - [x] How to pass payload - [x] Serialisation and deserialization - [x] White vs black box testing - [ ] verification and validation - [x] Authorisation vs authentication - [ ] Smoke vs sanity - [x] Different maven commands - [ ] SQL query - [x] Find xpath - [x] == and equals - [x] Concat - [ ] Sysout of 40+40 - [x] Can we overload the main method and override - [x] Do we need build to do perform - [x] Who should do unit testing