Pattern-first interview prep

Stop grinding.
Learn the patterns.

Three hundred problems will not save you if every one feels new. PrepStack teaches the 23 patterns underneath them — with step-through visualizations, templates worth memorizing, and a plan that fits the time you actually have.

Pick your timeline →Browse the patterns
patterns 23curated problems 308step-through visualizers 40tracks 3 or 6 months
Two ways in
12 weeks · 20–25 hrs/wk
3-month intensive

Laid off, between roles, or interviewing on a deadline

24 weeks · 8–10 hrs/wk
6-month sustained

Employed, prepping steadily without burning out

Why patterns

The bar moved. Volume alone stopped working.

You can finish 300 problems and still freeze on one you have never seen, because memorizing solutions does not transfer. Recognizing that a question is a sliding window in the first two minutes does.

Every pattern here gives you the recognition signals, a template you can write from a blank file, the mistakes that quietly cost offers, and a curated ladder of LeetCode problems ordered easiest to hardest.