Low Level Design Roadmap
20 sections • 357 topics
- 1. React Functional Components and Hooks (useState, useEffect)
- Example: Complete functional component with hooks
- 2. Vue 3 Composition API (setup, ref, reactive)
- Example: Vue 3 Composition API component
- 3. Angular 17 Standalone Components
- Example: Angular 17 standalone component with signals
- 4. Atomic Design System (Atoms, Molecules, Organisms) with Storybook
- Example: Storybook configuration and component story
- 5. TypeScript Props Interface and Type Definitions
- Example: Comprehensive TypeScript component interfaces
- 6. Higher-Order Components (HOC) Pattern and Render Props
- Example: HOC for authentication and loading states
- Component Architecture Best Practices
- 1. Redux Toolkit (createSlice, configureStore) and RTK Query
- Example: Redux Toolkit with RTK Query complete setup
- 2. Zustand Lightweight Store (create, set, get)
- Example: Zustand store with middleware and actions
- 3. React Context API Provider and useContext Pattern
- Example: Context API with TypeScript and custom hook
- 4. Recoil Atoms and Selectors (atom, selector, useRecoilState)
- Example: Recoil atoms, selectors, and families
- 5. MobX Observable State Trees (makeObservable, action)
- Example: MobX store with observer components
- 6. SWR Data Fetching and Caching (useSWR)
- Example: SWR with mutations and optimistic updates
- State Management Comparison
- 1. Flux and Redux Unidirectional Data Flow (Actions, Reducers, Store)
- Example: Complete Flux/Redux unidirectional data flow
- 2. GraphQL with Apollo Client Cache Normalization
- Example: Apollo Client with normalized cache and optimistic updates
- 3. React Query (useQuery, useMutation) and Optimistic Updates
- Example: React Query with optimistic updates and rollback
- 4. WebSocket Real-time Data Sync (Socket.io, ws)
- Example: WebSocket with React hook and reconnection logic
- 5. IndexedDB for Offline Data Persistence and Storage
- Example: IndexedDB wrapper with React hook
- 6. Observer Pattern and Event Emitters (EventEmitter, PubSub)
- Example: Event Emitter implementation with React integration
- Data Flow Architecture Patterns
- 1. React SyntheticEvent (preventDefault, stopPropagation)
- Example: React SyntheticEvent with type-safe handlers
- 2. Event Delegation (addEventListener, event.target)
- Example: Event delegation with dynamic elements
- 3. Custom Events (dispatchEvent, CustomEvent API)
- Example: Custom events for component communication
- 4. Debounce and Throttle Functions (Lodash, Custom)
- Example: Debounce and throttle implementations with React hooks
- 5. Keyboard Navigation (tabindex, focus, keydown)
- Example: Keyboard navigation with roving tabindex
- 6. Touch Events and Mobile Gestures (touchstart, touchmove)
- Example: Touch gestures with swipe and pinch detection
- Event Handling Best Practices
- 1. Next.js 14 App Router SSR SSG
- Example: Next.js 14 App Router with SSR, SSG, and ISR
- 2. Client-Side Rendering (CSR) with Vite and React
- Example: Vite React SPA with optimized configuration
- 3. Nuxt 3 Universal Rendering (Hybrid SSR/SSG)
- Example: Nuxt 3 universal rendering with data fetching
- 4. React 18 Concurrent Features
- Example: React 18 concurrent features in action
- 5. Virtual Scrolling (react-window, react-virtualized) for Large Lists
- Example: Virtual scrolling for large datasets
- 6. Streaming SSR with React Suspense and Server Components
- Example: Streaming SSR with Suspense boundaries
- Rendering Strategy Comparison
- 1. CSS Grid and Flexbox Layout (display: grid, flex)
- Example: CSS Grid and Flexbox responsive layouts
- 2. Tailwind CSS Responsive Utilities (sm, md, lg, xl)
- Example: Tailwind CSS responsive design patterns
- 3. Container Queries CSS Modern
- Example: Container queries for component-based responsiveness
- 4. Intersection Observer API for Lazy Loading Images
- Example: Intersection Observer for lazy loading
- 5. Mobile-First Breakpoint Strategy (min-width media queries)
- Example: Mobile-first responsive design
- 6. Adaptive Loading Based on Network Speed (navigator.connection)
- Example: Adaptive loading based on network and device
- Responsive Design Best Practices
- 1. WCAG 2.1 AA Standards and Semantic HTML5 Elements
- Example: WCAG 2.1 AA compliant semantic HTML structure
- 2. ARIA Labels (aria-label, aria-labelledby), Roles, and Screen Readers
- Example: ARIA attributes for accessible components
- 3. Focus Management (roving tabindex, focus-visible)
- Example: Focus management and roving tabindex
- 4. Color Contrast Checker (WebAIM, 4.5:1 ratio)
- Example: Color contrast compliance and testing
- 5. Keyboard Navigation Testing (Tab, Enter, Escape)
- Example: Keyboard navigation implementation
- 6. axe-core Automated Accessibility Testing and Audits
- Example: Automated accessibility testing with axe-core
- Accessibility Best Practices Summary
- 1. React Error Boundaries (componentDidCatch, getDerivedStateFromError)
- Example: React Error Boundaries implementation
- 2. Vue Error Handling (errorCaptured, errorHandler)
- Example: Vue error handling patterns
- 3. Error Monitoring (Sentry, LogRocket, Bugsnag)
- Example: Sentry and LogRocket integration
- 4. Toast Notifications (react-hot-toast, react-toastify)
- Example: Toast notifications for user feedback
- 5. Retry Logic with Exponential Backoff Algorithm
- Example: Retry logic with exponential backoff
- 6. Fallback UI and Skeleton Loading States (Suspense)
- Example: Skeleton screens and loading states
- Error Handling Best Practices
- 1. Core Web Vitals (LCP, CLS, FID, INP) - Google Metrics
- Example: Core Web Vitals measurement and optimization
- 2. Code Splitting (React.lazy, dynamic import, Suspense)
- Example: Code splitting strategies
- 3. React Memoization (React.memo, useMemo, useCallback)
- Example: Memoization techniques in React
- 4. Webpack Bundle Analyzer and Tree Shaking
- Example: Bundle analysis and optimization
- 5. Image Optimization (next/image, WebP, AVIF formats)
- Example: Modern image optimization techniques
- 6. Service Worker Caching Strategies with Workbox
- Example: Service Worker with Workbox caching strategies
- Performance Optimization Summary
- 1. XSS Prevention (DOMPurify Sanitization, escapeHtml)
- Example: XSS prevention with DOMPurify
- 2. CSRF Protection (SameSite Cookies, Anti-CSRF Tokens)
- Example: CSRF protection implementation
- 3. Content Security Policy (CSP) Headers and Nonce
- Example: Comprehensive CSP implementation
- 4. JWT Token Storage (HttpOnly Cookies vs localStorage)
- Example: Secure JWT token storage and handling
- 5. Input Validation (Joi, Yup, Zod Schemas)
- Example: Comprehensive input validation
- 6. HTTPS and Certificate Pinning for Secure Connections
- Example: HTTPS and security configuration
- Frontend Security Best Practices Summary
- 1. Axios and Fetch API with Error Handling (try-catch)
- Example: Axios vs Fetch API with comprehensive error handling
- 2. GraphQL Apollo Client and Code Generation (graphql-codegen)
- Example: GraphQL with Apollo Client and code generation
- 3. tRPC Type-safe API Calls (End-to-End TypeScript)
- Example: tRPC full-stack type-safe implementation
- 4. React Query Infinite Queries (useInfiniteQuery)
- Example: React Query comprehensive implementation
- 5. MSW (Mock Service Worker) for API Testing and Mocking
- Example: MSW for API mocking
- 6. API Rate Limiting and Retry Logic with Exponential Backoff
- Example: Advanced retry logic and rate limiting
- API Integration Best Practices Summary
- 1. Unit Testing (Jest, Vitest, describe, it, expect)
- Example: Jest and Vitest comprehensive unit testing setup
- 2. React Testing Library (render, screen, fireEvent, userEvent)
- Example: React Testing Library comprehensive user interaction tests
- 3. E2E Testing (Cypress, Playwright, Selenium)
- Example: Cypress and Playwright E2E testing
- 4. Component Testing with Storybook (Stories, Play function)
- Example: Storybook setup and component stories
- 5. Test Coverage (Istanbul, NYC, Coverage.js)
- Example: Istanbul coverage configuration and reporting
- 6. Visual Regression Testing (Chromatic, Percy, BackstopJS)
- Example: Visual regression testing setup
- Frontend Testing Best Practices Summary
- 1. CSS-in-JS (Styled-components, Emotion, styled-system)
- Example: Styled-components with dynamic theming
- Example: Emotion with css prop (faster than styled-components)
- 2. Tailwind CSS Utility-first Approach (JIT mode)
- Example: Tailwind configuration and custom utilities
- Example: Responsive design with Tailwind
- 3. CSS Variables (--custom-property) and Custom Properties
- Example: Design system with CSS variables
- Example: Runtime theme switching with JavaScript
- 4. Design Tokens and Figma to Code Integration
- Example: Design tokens structure (tokens.json)
- Example: Style Dictionary configuration and build
- 5. Dark Mode and Light Mode Toggle (prefers-color-scheme)
- Example: Complete dark mode implementation with persistence
- Example: Prevent flash of wrong theme (critical inline script)
- 6. Component Libraries (MUI, Chakra UI, Ant Design, shadcn/ui)
- Example: Material-UI (MUI) with custom theme
- Example: Chakra UI with composition and dark mode
- Example: shadcn/ui with Radix primitives (copy-paste approach)
- Styling Strategy Decision Matrix
- 1. i18n Libraries (React-intl, i18next, FormatJS)
- Example: react-i18next setup with TypeScript
- Example: react-intl (FormatJS) implementation
- 2. Dynamic Locale Loading and Lazy i18n Bundle Splitting
- Example: Dynamic locale loading with react-i18next
- Example: Webpack/Vite magic comments for chunk naming
- Example: Preloading strategy for better UX
- 3. Pluralization and ICU Message Format Syntax
- Example: ICU MessageFormat pluralization rules
- Example: react-intl with ICU MessageFormat
- Example: i18next with ICU plugin
- 4. RTL and LTR Support (dir attribute, CSS Logical Properties)
- Example: CSS logical properties for RTL support
- Example: React RTL implementation with context
- Example: Tailwind CSS with RTL plugin
- 5. Date and Timezone Formatting (date-fns, Intl.DateTimeFormat)
- Example: date-fns with locale formatting
- Example: Timezone handling with date-fns-tz
- Example: Native Intl API for formatting
- 6. TypeScript Translation Key Validation and Type Safety
- Example: TypeScript with i18next typed translations
- Example: Generate types from translation files
- Example: typesafe-i18n library (zero-dependency, full type safety)
- Example: Validation in CI/CD pipeline
- I18n Implementation Checklist
- 1. Monorepo Setup (Nx, Lerna, Turborepo, pnpm workspace)
- Example: Nx monorepo setup with React and shared libraries
- Example: Turborepo setup (simpler alternative)
- Example: pnpm workspaces (lightweight approach)
- 2. Feature-based Folder Structure (components, hooks, utils)
- Example: Feature-based structure (recommended for large apps)
- Example: Colocation pattern (keep related files together)
- Example: Next.js App Router with features
- 3. Barrel Exports and Index Files (index.ts)
- Example: Feature barrel export pattern
- Example: Tree-shaking friendly exports
- Example: Component library barrel exports
- 4. Absolute Imports and Path Mapping (tsconfig paths, @alias)
- Example: TypeScript path mapping configuration
- Example: Vite configuration with aliases
- Example: Next.js automatic path mapping
- Example: Jest configuration for path mapping
- 5. ESLint, Prettier, and Husky Pre-commit Hooks
- Example: Complete ESLint + Prettier + Husky setup
- Example: Husky + lint-staged configuration
- Example: Next.js ESLint configuration
- 6. TypeScript Strict Mode Configuration (strict: true)
- Example: Strict TypeScript configuration
- Example: Strict null checks and proper typing
- Example: Class strictPropertyInitialization
- Example: noUncheckedIndexedAccess
- Project Structure Best Practices
- 1. Vite Hot Module Replacement (HMR) and Fast Refresh
- Example: Vite configuration with HMR
- Example: React Fast Refresh with state preservation
- Example: Vite environment variables with HMR
- 2. Webpack Dev Server and Proxy Configuration
- Example: Webpack Dev Server proxy configuration
- Example: Vite proxy configuration
- Example: Create React App proxy setup
- 3. CI/CD with GitHub Actions (Workflows, Pipelines)
- Example: Complete CI/CD workflow for React app
- Example: Deployment workflow to Vercel/Netlify
- Example: Monorepo CI with Turborepo
- Example: Automated dependency updates with Dependabot
- 4. Pre-commit Hooks (lint-staged, Husky, commitlint)
- Example: Complete pre-commit hooks setup
- Example: Advanced lint-staged configuration
- Example: Monorepo lint-staged with Turborepo
- 5. Component Documentation with Storybook (MDX, Docs)
- Example: Storybook setup and configuration
- Example: Component stories with all variants
- Example: Interactive stories with play function
- Example: MDX documentation with embedded stories
- 6. Bundle Analyzer (webpack-bundle-analyzer) and Performance Monitoring
- Example: Webpack Bundle Analyzer setup
- Example: Vite bundle analysis with visualizer
- Example: Next.js bundle analysis
- Example: Bundle size budgets and monitoring
- Development Workflow Optimization Checklist
- 1. Micro-Frontends (Module Federation, Webpack 5, Single-SPA)
- Example: Webpack Module Federation setup
- Example: Vite Module Federation with plugin
- Example: Communication between micro-frontends
- 2. Web Components and Custom Elements (customElements.define)
- Example: Creating Custom Element with Shadow DOM
- Example: Web Component with Lit library (simplifies creation)
- Example: Slots for content projection
- 3. Islands Architecture (Astro, Qwik, Partial Hydration)
- Example: Astro Islands Architecture
- Example: Qwik resumability (no hydration)
- Example: Astro with React islands for interactivity
- 4. React Server Components (RSC) - Next.js 13+
- Example: Next.js App Router with Server Components
- Example: Data fetching patterns with Server Components
- Example: Mixing Server and Client Components
- 5. Edge Computing and Edge Functions (Vercel Edge, Cloudflare Workers)
- Example: Vercel Edge Function (Next.js)
- Example: Cloudflare Workers with KV storage
- Example: Edge function for personalization
- 6. WebAssembly (WASM) Integration for Performance
- Example: Rust WebAssembly module with wasm-pack
- Example: AssemblyScript for TypeScript developers
- Example: Real-world WASM use case - Image compression
- Advanced Architecture Decision Matrix
- 1. Service Workers (register, install, activate) and Workbox Caching
- Example: Workbox service worker setup
- Example: Custom Workbox service worker
- Example: React hook for service worker updates
- 2. Web App Manifest (manifest.json) and Installation Prompts
- Example: Complete manifest.json configuration
- Example: Install prompt handling with React
- Example: Vite PWA plugin setup
- 3. Push Notifications (Web Push API, FCM, OneSignal)
- Example: Frontend push notification setup
- Example: Service worker push event handler
- Example: Backend push notification server (Node.js)
- 4. Background Sync (sync event) and Offline Queue
- Example: Background Sync for offline form submission
- Example: Offline-first form component
- Example: Periodic Background Sync (Chrome only)
- 5. IndexedDB Storage Management (idb, Dexie.js)
- Example: IndexedDB with idb library (recommended)
- Example: React hook for IndexedDB
- Example: Dexie.js for advanced queries
- 6. App Shell Architecture for Fast Load Performance
- Example: App Shell structure with React
- Example: Service worker for App Shell caching
- Example: Performance optimization with App Shell
- PWA Implementation Checklist
- 1. Clean Code Principles and SOLID (Single Responsibility, DRY)
- Example: Single Responsibility Principle
- Example: Open/Closed Principle with composition
- Example: Dependency Inversion with dependency injection
- 2. Design Patterns (Factory, Observer, Singleton, Strategy)
- Example: Factory Pattern for dynamic component creation
- Example: Observer Pattern for event system
- Example: Strategy Pattern for payment processing
- 3. Performance Budgets and Lighthouse CI Automation
- Example: Lighthouse CI setup for automated performance testing
- Example: GitHub Actions CI workflow with Lighthouse
- Example: Webpack performance budgets
- 4. Route-based Code Splitting (React.lazy, dynamic import)
- Example: React route-based code splitting
- Example: Component-based code splitting with prefetching
- Example: Next.js dynamic imports with loading states
- 5. Tree Shaking and Dead Code Elimination (ES Modules)
- Example: Proper module structure for tree shaking
- Example: package.json sideEffects configuration
- Example: Optimizing library imports for tree shaking
- 6. Bundle Optimization (Webpack, Rollup, Vite, esbuild)
- Example: Advanced Webpack optimization configuration
- Example: Vite optimization configuration
- Example: Advanced bundle analysis and optimization
- Bundle Optimization Checklist
- 1. Hosting Platforms (Vercel, Netlify, Cloudflare Pages, AWS Amplify)
- Example: Vercel deployment configuration
- Example: Netlify deployment configuration
- Example: Cloudflare Pages deployment
- 2. Docker Containers for Frontend Apps (Dockerfile, docker-compose)
- Example: Multi-stage Dockerfile for React app
- Example: Nginx configuration for SPA
- Example: Next.js SSR Dockerfile
- Example: Docker Compose for full-stack development
- 3. CDN and Asset Optimization (CloudFront, Cloudflare CDN)
- Example: CloudFront distribution setup with Terraform
- Example: CDN cache control headers
- Example: Cloudflare Workers for edge optimization
- 4. Environment Variables (.env, process.env) and Configuration
- Example: Environment variables setup with validation
- Example: Multiple environment configurations
- Example: AWS Secrets Manager integration
- 5. Deployment Strategies (Blue-Green, Canary, Rolling Deployments)
- Example: Kubernetes Blue-Green deployment
- Example: Canary deployment with traffic splitting
- Example: Vercel deployment with preview URLs
- 6. Monitoring and Performance Tracking (Sentry, New Relic, Datadog)
- Example: Sentry integration with source maps
- Example: Custom performance monitoring
- Example: Comprehensive monitoring dashboard setup
- Production Deployment Checklist