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23.5-Capstone-Projects

21.5 Capstone Projects

Overview

Apply everything you've learned in comprehensive real-world projects that combine security, performance, design patterns, and best practices.

Learning Objectives

  • •Build complete, production-ready applications
  • •Apply security best practices throughout
  • •Implement performance optimizations
  • •Use appropriate design patterns
  • •Handle errors gracefully
  • •Write maintainable, testable code

Capstone Project 1: Task Management System

Description

A full-featured task management application with user authentication, team collaboration, and real-time updates.

┌─────────────────────────────────────────────────────────────┐
│                    TASK MANAGER APP                         │
├─────────────────────────────────────────────────────────────┤
│  ┌─────────────┐  ┌─────────────┐  ┌─────────────────────┐  │
│  │   AUTH      │  │   TASKS     │  │    REAL-TIME        │  │
│  │   MODULE    │  │   MODULE    │  │    SYNC             │  │
│  │             │  │             │  │                     │  │
│  │  - Login    │  │  - Create   │  │  - WebSocket        │  │
│  │  - Register │  │  - Update   │  │  - Notifications    │  │
│  │  - JWT      │  │  - Delete   │  │  - Live updates     │  │
│  │  - Sessions │  │  - Filter   │  │  - Presence         │  │
│  └─────────────┘  └─────────────┘  └─────────────────────┘  │
│                                                             │
│  ┌─────────────────────────────────────────────────────────┐│
│  │                    DATA LAYER                           ││
│  │  - IndexedDB for offline  - API sync  - Caching        ││
│  └─────────────────────────────────────────────────────────┘│
└─────────────────────────────────────────────────────────────┘

Features to Implement

  1. •

    Authentication System

    • •Secure login/register forms
    • •JWT token management
    • •Session handling
    • •Password validation
  2. •

    Task Management

    • •CRUD operations
    • •Drag-and-drop prioritization
    • •Labels and categories
    • •Due date reminders
  3. •

    Team Collaboration

    • •User assignment
    • •Comments
    • •Activity history
    • •Notifications
  4. •

    Data Persistence

    • •Offline-first with IndexedDB
    • •Sync with backend
    • •Conflict resolution

Capstone Project 2: E-Commerce Dashboard

Description

An admin dashboard for managing products, orders, and analytics with performance optimizations.

┌────────────────────────────────────────────────────────────────┐
│  E-COMMERCE DASHBOARD                              [User ▼]   │
├────────────────────────────────────────────────────────────────┤
│                                                                │
│  ┌──────────────────────────┐  ┌────────────────────────────┐  │
│  │     METRICS CARDS        │  │      SALES CHART           │  │
│  │  ┌────┐ ┌────┐ ┌────┐    │  │      ╭─────────────────╮   │  │
│  │  │$42K│ │1.2K│ │89% │    │  │   ▄▄▄│                 │   │  │
│  │  │Rev │ │Ord │ │Rate│    │  │ ▄█▀  │    Analytics    │   │  │
│  │  └────┘ └────┘ └────┘    │  │█▀    │                 │   │  │
│  └──────────────────────────┘  └────────────────────────────┘  │
│                                                                │
│  ┌──────────────────────────┐  ┌────────────────────────────┐  │
│  │     PRODUCTS TABLE       │  │    RECENT ORDERS           │  │
│  │  Virtual Scrolling       │  │    Live Updates            │  │
│  │  • Product 1    $99      │  │    • Order #1234  $156     │  │
│  │  • Product 2    $149     │  │    • Order #1235  $89      │  │
│  │  • Product 3    $79      │  │    • Order #1236  $234     │  │
│  │  ... 10,000 items        │  │                            │  │
│  └──────────────────────────┘  └────────────────────────────┘  │
│                                                                │
└────────────────────────────────────────────────────────────────┘

Features to Implement

  1. •

    Dashboard Components

    • •Metric cards with animations
    • •Charts (line, bar, pie)
    • •Real-time data updates
    • •Date range selectors
  2. •

    Product Management

    • •Virtual scrolling for large lists
    • •Image lazy loading
    • •Bulk operations
    • •Search and filters
  3. •

    Order Processing

    • •Order status workflow
    • •Email notifications
    • •Invoice generation
    • •Refund handling
  4. •

    Performance Optimizations

    • •Memoization
    • •Debounced search
    • •Lazy-loaded routes
    • •Service worker caching

Capstone Project 3: Real-Time Chat Application

Description

A secure messaging platform with end-to-end encryption, file sharing, and rich media support.

┌─────────────────────────────────────────────────────────────────┐
│  SECURE CHAT                                         🔒 E2E    │
├───────────────┬─────────────────────────────────────────────────┤
│               │                                                 │
│  CONTACTS     │  CONVERSATION                                   │
│  ───────────  │  ──────────────────────────────────────────    │
│               │                                                 │
│  🟢 Alice     │  Alice:          Hello! How are you?    10:30  │
│  🟢 Bob       │  ─────────────────────────────────────────────  │
│  🔴 Charlie   │                                                 │
│  🟡 Diana     │  You:   I'm good! Check this out:       10:31  │
│               │         ┌─────────────────┐                     │
│  ───────────  │         │  📷 image.jpg   │                     │
│  CHANNELS     │         └─────────────────┘                     │
│  ───────────  │  ─────────────────────────────────────────────  │
│               │                                                 │
│  # general    │  Alice: Nice! 👍                          10:32 │
│  # dev        │                                                 │
│  # random     │  ─────────────────────────────────────────────  │
│               │                                                 │
│               │  ┌──────────────────────────────────────────┐  │
│               │  │  Type a message...               📎  😀  │  │
│               │  └──────────────────────────────────────────┘  │
└───────────────┴─────────────────────────────────────────────────┘

Features to Implement

  1. •

    Messaging System

    • •Real-time message delivery
    • •Message status (sent, delivered, read)
    • •Typing indicators
    • •Message reactions
  2. •

    Security

    • •End-to-end encryption
    • •Key exchange protocol
    • •Secure message storage
    • •Session management
  3. •

    Media Support

    • •Image/file upload
    • •Image preview and gallery
    • •Audio messages
    • •Link previews
  4. •

    User Features

    • •Presence indicators
    • •User profiles
    • •Contact management
    • •Block/mute users

Capstone Project 4: Code Playground

Description

An interactive code editor and execution environment similar to CodePen or JSFiddle.

┌─────────────────────────────────────────────────────────────────┐
│  CODE PLAYGROUND                          [Save] [Share] [Fork] │
├─────────────────────────────────────────────────────────────────┤
│                                                                 │
│  ┌─────────────────────────┐  ┌─────────────────────────────┐   │
│  │  HTML                ▾  │  │  PREVIEW                    │   │
│  │ ───────────────────────│  │ ────────────────────────────│   │
│  │ <div id="app">         │  │                             │   │
│  │   <h1>Hello World</h1> │  │   ┌─────────────────────┐   │   │
│  │ </div>                 │  │   │   Hello World       │   │   │
│  │                        │  │   │                     │   │   │
│  ├─────────────────────────┤  │   │   Counter: 5        │   │   │
│  │  CSS                 ▾  │  │   │   [+] [-]           │   │   │
│  │ ───────────────────────│  │   │                     │   │   │
│  │ #app { padding: 20px; }│  │   └─────────────────────┘   │   │
│  │ h1 { color: blue; }    │  │                             │   │
│  │                        │  │                             │   │
│  ├─────────────────────────┤  │                             │   │
│  │  JavaScript          ▾  │  │                             │   │
│  │ ───────────────────────│  │  Console:                   │   │
│  │ const app = document.. │  │  > Counter initialized      │   │
│  │ let count = 0;         │  │  > Button clicked           │   │
│  │                        │  │                             │   │
│  └─────────────────────────┘  └─────────────────────────────┘   │
│                                                                 │
└─────────────────────────────────────────────────────────────────┘

Features to Implement

  1. •

    Code Editor

    • •Syntax highlighting
    • •Auto-completion
    • •Error highlighting
    • •Multiple file support
  2. •

    Execution Environment

    • •Sandboxed iframe execution
    • •Console capture
    • •Error display
    • •Hot reloading
  3. •

    Collaboration

    • •Save and share
    • •Fork projects
    • •Comments
    • •Version history
  4. •

    Security

    • •Sandbox isolation
    • •XSS prevention
    • •Rate limiting
    • •Input sanitization

Project Architecture Patterns

Module Pattern

Project Structure:
─────────────────
src/
├── modules/
│   ├── auth/
│   │   ├── authService.js
│   │   ├── authStore.js
│   │   └── authUI.js
│   ├── tasks/
│   │   ├── taskService.js
│   │   ├── taskStore.js
│   │   └── taskUI.js
│   └── shared/
│       ├── api.js
│       ├── storage.js
│       └── events.js
├── utils/
│   ├── validators.js
│   ├── formatters.js
│   └── helpers.js
├── app.js
└── index.html

Event-Driven Architecture

┌─────────────┐     Events      ┌─────────────┐
│   Module A  │ ───────────────▶│  Event Bus  │
└─────────────┘                 └─────────────┘
                                       │
              ┌────────────────────────┼────────────────────────┐
              │                        │                        │
              ▼                        ▼                        ▼
       ┌─────────────┐          ┌─────────────┐          ┌─────────────┐
       │   Module B  │          │   Module C  │          │   Module D  │
       └─────────────┘          └─────────────┘          └─────────────┘

Security Checklist

Input Validation

  • • Validate all user inputs
  • • Sanitize HTML content
  • • Use parameterized queries
  • • Validate file uploads

Authentication

  • • Secure password storage
  • • JWT with proper expiration
  • • HTTPS everywhere
  • • Session management

Data Protection

  • • Encrypt sensitive data
  • • Secure storage
  • • No secrets in code
  • • Proper error handling

XSS Prevention

  • • Output encoding
  • • Content Security Policy
  • • DOM manipulation safety
  • • Trusted types

Performance Checklist

Loading Performance

  • • Code splitting
  • • Lazy loading
  • • Image optimization
  • • Resource hints

Runtime Performance

  • • Virtual scrolling
  • • Debounce/throttle
  • • Memoization
  • • Web Workers

Caching

  • • Service workers
  • • Local storage strategy
  • • HTTP caching
  • • Memory management

Testing Requirements

Unit Tests

  • •Test all utility functions
  • •Test validators
  • •Test state management
  • •Mock external dependencies

Integration Tests

  • •Test module interactions
  • •Test API integrations
  • •Test data flow
  • •Test error scenarios

E2E Tests

  • •Test user workflows
  • •Test authentication flow
  • •Test critical paths
  • •Test edge cases

Evaluation Criteria

CriteriaWeightDescription
Functionality30%All features work correctly
Code Quality25%Clean, maintainable, well-organized
Security20%Follows security best practices
Performance15%Optimized, fast, efficient
Testing10%Good test coverage

Resources

.5 Capstone Projects - JavaScript Tutorial | DeepML