Are there any alternatives to "Good luck with your interview."

 Here are a few alternatives to "Good luck with your interview," each with a slightly different tone:

More formal or professional:

• "Best wishes for your interview."

• "I hope your interview goes well."

• "Wishing you the best in your interview."

More casual or personal:

• "I'm rooting for you!"

• "You've got this."

• "Go get 'em!"

• "Hope it's a great conversation."

Focusing on their preparation:

• "I'm sure you'll do great."

• "I know you've prepared well. Just be yourself."

• "Sending you good vibes for your interview."