LEARN PATTERNS, NOT PROBLEMS

Most platforms throw 3,000 problems at you and hope something sticks. We teach you the 22 patterns that solve them all.

THREE TRACKS

CODING BASICS

Build your foundation with 12 categories of pre-algorithm problems. Strings, arrays, recursion, sorting — the building blocks you need before tackling patterns.

12 categories

ALGORITHMS

Master 22 algorithm patterns across 3 tiers. Each pattern includes curated problems with starter code, test cases, and solutions in 5 languages.

22 patterns · 3 tiers

PATTERN RECOGNITION

The real interview skill: reading a problem and knowing which pattern to apply. 176 quiz questions that train your pattern-matching instincts.

176 questions

BUILT FOR DEPTH

AI Hints

Stuck? Get progressive hints from Claude AI that guide you toward the solution without giving it away.

5 Languages

Write and run code in Python, JavaScript, TypeScript, Java, or Go. Every problem has starter code and solutions in all five.

Spaced Repetition

SM-2 algorithm schedules reviews at the right intervals so patterns stick in long-term memory.

Reference Cards

Quick-reference pages for every pattern with API cheatsheets, code recipes, and complexity tables.

Guided Curriculum

Problems are ordered by difficulty within each pattern. Foundations first, then intermediate, then advanced.

Real Code Execution

Run your code against test cases in a sandboxed environment. See output, errors, and test results instantly.

Free tier includes 3 algorithm patterns, all coding basics, and 15 recognition questions.