First is a phone screen with a recruiter. Then a 1:1 phone call for 30 min with the hiring manager. Then a 4 hour interview on site.

You meet with 7 people with half hour time slots. Six of them technical, one HR. Most of the interviewers are interested in your technical problem solving abilities and critical thinking skills. Personality fit with the organization is also tremendously important. The company is evolving quickly and so are the requirements of candidates.

Questions that combine optics, statistics, simple math concepts.

The questions are indirect requiring the applicant to identify the concept in the case prior to being able to solve the problem.