Leet Learner: Coding Interview

Master technical interviews with Leet Learner, your comprehensive guide to coding interview success and professional software development.

CODING INTERVIEW PROBLEMS

Browse an extensive collection of technical interview problems organized by:
• Difficulty (Easy, Medium, Hard)
• Categories (Array, String, Tree, Graph, Dynamic Programming, etc.)
• Top 75, Top 150, and SQL 50 curated lists
• Advanced filtering (notes, review status, confidence scores)
• Smart search with instant results
• Visual indicators for notes and progress

Each problem includes:
• Complete solution with detailed explanation
• Time and space complexity analysis
• Step-by-step problem solving approach
• Alternative solution strategies
• Personal notes with view/edit modes

COMPREHENSIVE TECHNICAL REFERENCE

Master the fundamentals with in-depth guides covering:

SOFTWARE ENGINEERING & ARCHITECTURE
• Data Structures & Algorithms
• Design Patterns (Creational, Structural, Behavioral, Architectural)
• Microservices & Event Driven Architecture
• System Design & Scalability
• API Design & GraphQL
• Message Queues & Kafka
• Application Security
• Software Principles & Best Practices

LANGUAGES & FRAMEWORKS
• Python, SQL, TypeScript, Shell, Java, Go
• React, React Native, Next.js, Node.js
• PySpark, Spark SQL, FastAPI, LangChain

DATA ENGINEERING & DATABASES
• AWS, Azure, GCP, Databricks, Snowflake
• PostgreSQL, SQL Server, MongoDB, Redis
• Data Engineering Patterns & ETL
• Data Modeling & Warehousing
• Delta Lake & Data Visualization

CLOUD & INFRASTRUCTURE
• Cloud-Native Architecture
• Kubernetes & Container Orchestration
• Docker & Terraform
• Platform Engineering
• CI/CD Pipelines & GitHub Actions
• Git Workflows & Observability
• Testing Strategies

AI & MACHINE LEARNING
• LLM Applications & Prompt Engineering
• RAG Pipelines & Vector Databases
• MLOps & Model Deployment
• Agentic Automation & AI Workflows
• Claude & AI Coding
• Model Context Protocol (MCP)

All guides feature code examples, best practices, quick reference tables, architectural diagrams, and patterns used in modern software systems.

TRACK YOUR PROGRESS

Stay motivated with powerful progress tracking:
• Mark problems as reviewed with checkmark indicators
• Rate your confidence (1-10 scale) with color-coded badges
• Add personal notes with dedicated view/edit modes
• Visual indicators showing which problems have notes
• Filter by review status, confidence level, or note presence
• Track completion by category and difficulty

INTERACTIVE QUIZ MODE

Smart, customizable quizzes:
• Filter by difficulty level (Easy, Medium, Hard)
• Select specific categories (Array, Tree, Graph, etc.)
• Filter by confidence score ranges (low, medium, high)
• Filter by review status (reviewed/not reviewed)
• Filter by note presence (with notes/without notes)
• Weighted random selection prioritizes weaker areas
• Review detailed explanations after each problem

CLEAN, FOCUSED DESIGN

Easy learning environment:
• Dark mode optimized for reading code
• Syntax highlighted code examples
• Smooth navigation and search
• Responsive layout
• Optimized for speed

STUDY SMARTER

• Reference design patterns and software architecture principles
• Implement microservices and event driven systems
• Design scalable cloud-native applications
• Learn modern cloud platforms (AWS, Azure, GCP) and Kubernetes
• Build data pipelines with Databricks, Snowflake, and Delta Lake
• Develop with React, Next.js, Node.js, and FastAPI
• Adopt DevOps practices and platform engineering
• Explore AI/ML applications, LLMs, and RAG pipelines
• Prepare systematically for technical interviews
• Develop professional software engineering skills

Start your journey to interview success and technical mastery today!