Leet Learner vs Codey

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!

Learn to code the fun way — no experience needed. Codey turns learning to program into a game. Instead of staring at a blank screen, you drag colorful code blocks into place to write real Swift — the same language used to build iPhone and Mac apps. Solve bite-sized puzzles, earn XP, build a daily streak, and watch your skills grow one lesson at a time. WHY CODEY • Real code, not toy syntax — you write actual Swift from day one • Game-style lessons — drag blocks, solve puzzles, earn XP and badges • Truly for beginners — every idea explained in plain language • Learn by doing — a free Playground to experiment anytime • Your two modules are completely free • No-ads.!!! ALWAYS WHAT YOU'LL LEARN 15 modules • 90 lessons • hundreds of hands-on challenges — from your very first line of code to building real apps: • Fundamentals: types, printing, variables, conditionals • Loops & collections, functions & closures • Optionals, object-oriented programming, and advanced topics • Building apps: SwiftUI, networking, saving data, app architecture, testing, accessibility & animations ALSO INSIDE • Daily challenges to keep your streak alive • Mastery quizzes to lock in each module • Shareable certificates when you finish a module • A home-screen widget for your streak • Available in English and Greek Start free today and write your first line of code in minutes.