- Do you use Behavior Driven Development ?
- Do you use Test Driven Development ?
- How do you do sad path testing ?
- How do you structure test plans ?
- How do you approach the 4 quadrants of Agile Testing ?
- Do you use the Test Pyramid ?
- What do you try to capture for a typical UI bug ?
- What sort of relationship do you look to have with the QA group ?
- How do you try and address intermittent failures in the test suite ?
- What experience do you have with performance testing ?
- What's the most interesting bug you've seen at work ?
- Do you have one assertion per test and do you make exceptions ?
- What is your experience with team-based vs. more role based development ?

I would leave the more detailed coding questions to the dev team.  
Focus on your area of quality and testing