Preparation is key when going for an interview with a prospective employer. Their job is to ensure you are going to be not only a skill fit, but a cultural fit for the company. Your job on the other hand is to ensure that interviewer has confidence that you are not only that skills fit, but a cultural fit for them as well. This all depends on how well you prepare for the interview.
Every interview you prepare for should be tailored to that company. You should be able to clearly and succinctly be able to answer the most common interview questions while also avoiding leaving a poor first impression with very common interview mistakes. You only have 1 chance at a first impression. You want to eliminate most of the nervousness and stress before and during the interview by practicing those difficult answers and ensuring you know not only your cv, but how to spot the difference between behavioural and situational questions and answer them accordingly. Most of all remember preparation, anticipation and confidence are the key skills to ensure a successful interview.
Make sure you can describe your contributions in present and previous jobs
Day to day duties, customer support, product development, verifying information, etc.
Your Future Job
Make sure you understand the job you are being interviewed for: