Most candidates either overprepare and burn out or underprepare and fail. The key is finding your minimum viable preparation time based on your specific background. After interviewing hundreds of engineers, the author found that CS degree holders with 2+ years experience need 4-8 weeks, while career changers require 16-24 weeks to build fundamentals from scratch.

Your timeline depends heavily on your starting point. Those with recent prep experience within two years can refresh in just 2-4 weeks, while Staff+ candidates need 8-12 weeks minimum for system design depth and leadership stories. Full-time workers should add 2-4 weeks to any timeline. The author emphasizes that 6-10 weeks works for most, with less than 4 weeks only viable for those with exceptional fundamentals.

The most common mistake is grinding random problems without learning patterns first. Effective prep requires learning core patterns like two pointers and sliding window before practicing. Mock interviews should start by the halfway point to reveal gaps. For emergency situations, focus on the Blind 75 core problems only—this is damage control, not optimal preparation. Postponing interviews is better than entering unprepared if possible.