CodeCrush Pro vs Quarry

Practice coding interviews anywhere with CodeCrush — a clean, focused app built for learning data structures and algorithms in Python. Solve Real Problems 85+ hand-picked problems across Easy, Medium, and Hard — covering arrays, strings, trees, graphs, dynamic programming, linked lists, and more. Each problem includes examples, hints, and an optimal solution explanation. Write Code, Get Instant Feedback A built-in Python editor with syntax highlighting, a real-time linter, and pinch-to-zoom font sizing. Run your code against test cases and see results instantly. Stay Consistent with Daily Challenges A new challenge every day to keep you sharp. Build streaks, filter by difficulty, and share your progress with friends. Track Your Growth Earn XP across skill categories like Arrays, Trees, Dynamic Programming, and more. Level up skills, unlock achievements, and see your progress on a detailed profile. Features: - 85+ coding problems (Easy, Medium, Hard) - Python code editor with syntax highlighting - Built-in Python linter - Instant code execution with test cases - Daily challenges with streak tracking - XP system with skill-based leveling - 18 unlockable achievements - Hints and solution explanations - Difficulty filtering - Share streaks and solutions - iPad support - Works beautifully in dark mode Whether you're preparing for technical interviews or just love solving problems, CodeCrush makes it easy to practice a little every day.

Data interview practice that runs entirely on your device. Write real SQL and Python (pandas), get graded instantly, and see exactly why. NEW IN 1.1 • Designed for iPhone Duo: question and editor side by side when open, a focused layout when closed, and it adapts as you fold. • A new native design for iPhone and iPad, in light and dark mode. • 60 new problems: a staff-level data engineering set (gaps and islands, sessionisation, slowly changing dimensions, funnels, retention) and company-style SQL sets. • Clearer results: instant correct / not quite feedback, expected vs. actual tables, and the query plan for your SQL. WHAT'S INSIDE • 168 problems across three tracks: 61 SQL, 22 pandas and 85 Python (algorithms and data structures). • Real execution, real grading. Your output is checked against the expected result, with no self-marking. • Company-style practice. Filter problems written in the style of the company you're interviewing at. • Hints and full solutions when you're stuck. • Difficulty levels from Easy to Hard, grouped by topic. • A free-form Playground for scratch SQL and Python. PRIVATE BY DESIGN No accounts. No analytics. No ads. No tracking. Quarry collects nothing and works fully offline. Built by a working data engineer, for analysts, data engineers, data scientists and software engineers who want a quiet, fast place to actually practice.