The Big Tech interview process has stages:
Online Assessment (OA): - problems, - minutes, automated scoring. This filters candidates before investing engineer time. Most companies use HackerRank or CodeSignal.
Phone Screen: - minutes, - problems with a live engineer. You must explain your thought process while coding. Communication matters as much as correctness.
Onsite Loop: - interviews covering coding, system design, and behavioral questions. Each interview has a different focus and interviewer.