DVA Trainer - AWS Developer Associate Certification Platform

Master AWS Developer Associate certification with interactive practice questions, gamified manga onboarding, and spaced repetition flashcards.

🌐 Live Demo: dva-trainer-web.onrender.com

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📸 Overview

DVA Trainer is a comprehensive learning platform designed to help developers prepare for the AWS Developer Associate (DVA-C02) certification exam. Built with modern web technologies and cloud-native architecture principles.

Key Features

• 📚 557 Practice Questions - Covering all exam domains with detailed explanations
• 🎮 Gamified Learning - Manga-style story onboarding (13 chapters across 2 seasons)
• 🃏 Spaced Repetition Flashcards - 30 flashcards with metaphors tied to the story
• 📝 Exam Simulator - 65-question timed assessments (130 minutes)
• 📅 Daily Training Routines - 5/10/15 question daily sessions
• 🔐 Secure Authentication - GitHub OAuth 2.0 + JWT implementation
• 📱 Responsive Design - Works on desktop, tablet, and mobile
• ♿ Accessible - WCAG 2.1 AA compliant

Screenshots

User Dashboard with progress tracking	AWS's glossary
Manga-style onboarding story	Spaced repetition flashcards

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🏗️ Architecture

Backend (NestJS + TypeScript)

src/
├── auth/                 # OAuth2/JWT authentication
├── questions/            # Question management & filtering
├── flashcards/           # Spaced repetition system
├── onboarding/           # Manga story content
├── users/                # User management & progress
├── exam-simulator/       # Timed exam sessions
├── database/             # TypeORM entities & migrations
└── config/               # Environment configuration

Key Backend Features:

• Authentication: OAuth2 with GitHub, JWT token management
• Database: PostgreSQL with TypeORM
• Testing: Jest with 86% code coverage
• API: RESTful with OpenAPI/Swagger documentation
• Security: Helmet, CORS, input validation

Frontend (Angular 17+ Standalone)

src/
├── app/
│   ├── auth/             # Login & authentication flows
│   ├── dashboard/        # User progress & KPIs
│   ├── questions/        # Practice question interface
│   ├── flashcards/       # Flashcard learning system
│   ├── onboarding/       # Manga story experience
│   ├── exam-simulator/   # Full exam simulation
│   └── shared/           # Components, services, models
├── assets/               # Images, manga illustrations
└── styles/               # SCSS variables & themes

Key Frontend Features:

• Standalone Components - Modern Angular architecture
• State Management - RxJS for reactive state
• Theming - Dark/Light/Auto mode support
• Performance - Lazy loading, code splitting
• Testing - Karma & Jasmine unit tests

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🚀 Getting Started

Prerequisites

• Node.js 18+
• PostgreSQL 14+
• GitHub OAuth App credentials

Installation

# Clone the repository
git clone https://github.com/uouake/dva-trainer-web.git
cd dva-trainer-web

# Backend setup
cd backend
cp .env.example .env
# Edit .env with your database credentials and GitHub OAuth keys
npm install
npm run migration:run
npm run start:dev

# Frontend setup (new terminal)
cd ../frontend
npm install
ng serve

Environment Variables

Backend (.env):

DATABASE_URL=postgresql://user:password@localhost:5432/dva_trainer
JWT_SECRET=your-secret-key
GITHUB_CLIENT_ID=your-github-client-id
GITHUB_CLIENT_SECRET=your-github-client-secret
PORT=3000

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🧪 Testing

Backend Tests

cd backend
npm run test              # Unit tests
npm run test:coverage     # Coverage report
npm run test:e2e          # End-to-end tests

Frontend Tests

cd frontend
ng test                   # Unit tests with Karma
ng test --coverage        # Coverage report

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📊 Project Stats

• Lines of Code: ~25,000
• Test Coverage: 86% (backend)
• API Endpoints: 40+
• Database Tables: 15
• Deployment: Render (Web Service + PostgreSQL)

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🛣️ Roadmap

• Core question database (557 questions)
• OAuth2/JWT authentication
• Exam simulator
• Flashcards system
• Manga onboarding (Seasons 1 & 2)
• Production deployment
• Seasons 3+ of onboarding story
• Competition mode between users
• Achievement badges system
• Progress export functionality
• Email reminder notifications

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🎓 Lessons Learned

Technical

• OAuth2 Implementation: Deep understanding of authorization code flow with GitHub
• Database Design: Optimized schema for spaced repetition algorithms
• CI/CD: Automated testing and deployment pipelines on Render
• Performance: Lazy loading strategies for large question datasets

Architecture

• Microservices readiness: Designed with future service extraction in mind
• Multi-tenancy considerations: User isolation and data security patterns
• Scalability: Stateless backend design for horizontal scaling

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🛡️ Security

• JWT tokens with secure httpOnly cookies
• Input validation and sanitization
• SQL injection protection via TypeORM
• XSS protection with Angular's built-in sanitization
• Rate limiting on authentication endpoints

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📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

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🙏 Acknowledgments

• AWS certification materials and practice questions
• NestJS and Angular communities
• Render for free hosting tier
• All contributors and beta testers

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Built with ❤️ by Uriel Ouake