General advice before an interview:

• The most confident are the best at interviewing, but not necessarily the best hires. Be aware.
• Be curious, try to dive deeper on every answer by asking “why”, “how”, etc.
• Be flexible with the questions you ask based on the answers you’re getting.
• Figure out what you are looking for before interviewing anyone, and adjust your questions based on that.

Questions:

• What is it about [XXX] that interests you? What motivates you?
• If I gave you two free weeks to learn ANYTHING, what would it be and why?
• What environments do you prefer working in? (structured vs unstructured, quantitative vs qualitative, hierarchical vs non-hierarchical)
• What would you hope to accomplish in the first 30/60/90 days of your time here? How would you expect to be spending your time to accomplish everything?
• Tell me about the last time you disagreed with a decision that was made in your company, or a project/initiative of yours was cut short (or failed). [seek optimism, pragmatism, and understanding in their answer].
• What accomplishments are you most proud of?