In my career I have been interviewed many times and had an opportunity to be Interviewer to hire someone in the testing area. I personally feel apart from having a good personality and communication, candidate should showcase following –
1. Why do you want to be a Tester or continue being a Tester?
This is show the Passion for the role and proactively curious approach toward finding issues and overall quality.
It also will show if they have a desire for continuous learning.
2. Write 7 Test Cases to test a cell phone
This will show if they have a logical approach
What details they include in a test case
If they are thorough or gravitate toward just one type of testing (error conditions or functionality or stress etc)
3. How many Gas Stations in San Francisco
This will show the analytical and creative thinking
What assumptions they make
What factors they use to make their calculation
4. How can Automation effectively be used in testing?
This will show the overall involvement and experience in QA
Do they focus solely on automation or combine it with manual, white box, code reviews etc.
5. What do you do when you are blocked from testing what you have been assigned?
This will show if they stop or blame
Or if they find creative solutions for moving ahead
Or if they jump to another area to test or to help another tester