Learn DSA & CodeVisually for Free
Master Data Structures & Algorithms with our beginner-friendly tutorials and goal-oriented roadmaps. Browse standalone tutorials, follow a dedicated goal roadmap, practice 4-language code and crack product-company interviews.
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Start learning the most important software engineering tracks from ground zero.
Don't Memorize Code. See How It Works Step-by-Step.
Most sites dump a wall of code on you. On BigOSlate, every single topic starts from zero and lets you click through the algorithm in memory before you write a single line of code:
Everyday analogy + why the slow brute-force approach fails.
Step forward & backward through pointers, DP tables, and trees.
Side-by-side Python, C++, Java & JavaScript implementations.
items[i] instant? Click any locker below:An array stores items side-by-side in RAM. The computer jumps straight to any slot using base_address + i × 4!
Explore Our Engineering Roadmaps
Start with our complete, 100% free DSA Mastery Roadmap today, or browse standalone topics in the Tutorials Catalog.
DSA & Coding Interview Mastery Roadmap
Start from zero and master every interview pattern asked at Google, Amazon, Meta, Microsoft, and Uber. Follow our 13-step goal roadmap with plain-English tutorials, interactive visual steppers, and 4-language templates (Python, C++, Java, JS).
- 13 Milestones / 23 Visual Tutorials
- Interactive Step-by-Step Visual Drawings
- Python, C++, Java & JavaScript Code
- 3-Day & 14-Day Spaced Repetition Queue
High-Level System Design (HLD) — Zero to 100M Users Roadmap
Learn load balancing, caching, sharding, Kafka event streams, CAP theorem, and design real systems (WhatsApp, Uber, YouTube, Stripe) with interactive architecture diagrams.
- Scalability & Distributed Databases
- Interactive Request-Flow Diagrams
- 20 Real FAANG Architecture Breakdowns
Low-Level Design (LLD), SOLID & Machine Coding Roadmap
Master SOLID principles, GoF Design Patterns, concurrency/thread safety, UML class diagrams, and 90-minute machine coding interviews (Parking Lot, Splitwise, BookMyShow).
- SOLID & 12 Essential Design Patterns
- Thread-Safe Concurrency Patterns
- Production-Ready Java, C++ & Python Code
SQL, B-Trees & Database Internals Track
Understand how B+ Trees, LSM Trees, WAL logs, MVCC transactions, and query optimizers actually work inside PostgreSQL and MySQL.
- Window Functions & Query Plans
- B+ Tree vs. LSM Tree Storage
- Isolation Levels & Deadlock Prevention
Interactive Tools to Practice & Retain Patterns
DEPENDENCY ROADMAP
Follow all 13 modules in strict prerequisite order with live completion bars.
45-MIN BLIND MOCK
Simulate a real FAANG round with hidden topic tags and a 45-minute countdown.
SPACED REPETITION
Automatic +3-day and +14-day review queue so you never forget a pattern.
BIG-O CHEAT SHEET
1-page complexity lookup and copy-ready templates in Python, C++, Java & JS.