In the course of my five years in software development and tech education (I mentored at Thinkful, a top online coding bootcamp/career accelerator), I've given upwards of 60 technical interviews. This is my first article on DEV Community, and I'm writing this because even experienced developers ask colleagues for tips before going into an interview.
Here are four suggestions for the most common types of interviews, not including whiteboard interviews:
1) Prepare as much as possible, but save some time before the interview to do something other than prep. Go for a walk or jog or bike ride; take a power nap; meditate; yoga; any positive activity). I've seen that make a difference in approaching the interview with a fresh perspective and the ability to listen and remain centered during the interview.
2) For technical comprehension questions, take a moment to focus on the key details, before giving an answer. Silence from the interviewer isn't a signal that an answer is incomplete. The interviewer may need time to jot down notes before asking the next question.
3) Ask clarifying questions. The interviewer isn't allowed to intervene if you start answering a question different from the one intended (questions are sometimes vague). But interviewers can confirm that you're headed in the right direction. Technical interviewers often cite this as the most overlooked piece of advice.
4) Talk through your problem-solving process. Part of the interview is learning about the interviewee's communication of technical concepts and approach; it's not just about code.
In the end, it's just one interview. Good luck!