i had a 7 hour interview before. it was hell.

think of situations/stories that showcase that you have the skills for the job to use in your interview when they ask you behavioral questions. ask questions that show that you've researched the company and have interest in them, their future projects, etc. you don't want canned answers, but i'd have general ideas of what to say for the typical stuff they ask like 75% of the time (tell me about yourself, tell me about a time when you did x and what was the result, why do you think you're a good fit for this position, etc.)

good luck! :)