StagePass - Event Ticketing System

A modern event ticketing system built with Laravel, focusing on real-time seat booking and management.

Architecture & Design Decisions

1. Database Design

• Soft Deletes: Implemented on key models (Event, Seat, Booking) to maintain data integrity and history
• Relationships:
  • One-to-Many between Events and Seats
  • One-to-Many between Events and Bookings
  • One-to-Many between Users and Bookings
  • One-to-One between Seats and Bookings
• Optimizations:
  • Indexed foreign keys for faster joins
  • Composite indexes for status + expiration checks
  • Chunked inserts for large seat generations

2. Authentication & Authorization

• Multi-User Roles:
  • Admin users (is_admin flag) for event management
  • Regular users for booking tickets
• Route Protection:
  • Admin middleware for protecting admin routes
  • Custom RedirectIfAdmin middleware for UX
• Session Management:
  • Secure session handling with CSRF protection
  • Remember-me functionality
  • Session-based flash messages

3. Event Management

• Status Lifecycle:
  • Draft: Initial event creation
  • Published: Available for booking
  • Cancelled: No longer available
• Seat Map Generation:
  • Dynamic grid creation (max 20x20)
  • Automatic cleanup of old seats
  • Bulk insert optimization
• Validation Rules:
  • Maximum dimensions enforcement
  • Date and capacity validation
  • Price range constraints

4. Booking System

• State Machine:
  • Seat States: available → reserved → booked
  • Booking States: pending → completed/failed
  • Payment States: pending → paid/failed/refunded
• Concurrency Control:
  • Pessimistic locking for seat operations
  • Temporary reservations with TTL
  • Transaction isolation for booking operations
• Payment Processing:
  • Multiple payment method support
  • Secure payment confirmation flow
  • Automatic cleanup of abandoned bookings

5. Real-time Features

• Seat Management:
  • Live seat status updates (5s polling)
  • Immediate booking feedback
  • Concurrent booking protection
• User Interface:
  • Interactive seat selection
  • Real-time availability updates
  • Dynamic pricing display

6. Command Layer

• Scheduled Tasks:
  • Expired reservation cleanup (every minute)
  • Failed payment handling
  • Automatic event status updates
• Maintenance Commands:
  • Booking simulation for testing
  • Database cleanup utilities
  • System health checks

7. Service Layer

• Business Logic Isolation:
  • BookingService for core booking logic
  • EventService for event management
  • PaymentService for payment processing
• Transaction Management:
  • Atomic operations
  • Rollback capabilities
  • Dead lock prevention

8. Testing Strategy

• Unit Tests: Core business logic testing
• Feature Tests: End-to-end testing of key features
• Integration Tests: Testing component interactions
• Concurrency Tests: Simulation of concurrent bookings

Concurrency Handling

The system implements a multi-layered approach to handle concurrent bookings and prevent race conditions:

1. Database Level Protection

• Pessimistic Locking:

  • Uses lockForUpdate() when reserving seats to prevent double bookings
  • Ensures atomic operations during critical seat status updates

  Seat::where('id', $seatId)
      ->where('status', Seat::STATUS_AVAILABLE)
      ->lockForUpdate()
      ->first();

• Transaction Isolation:

  • Wraps all booking operations in database transactions
  • Prevents phantom reads and non-repeatable reads

  DB::transaction(function () {
      // Seat reservation logic
  });

2. Application Level Protection

• Temporary Reservation System:

  • Time-limited seat reservation (5 minutes)
  • Automatic cleanup of expired reservations via scheduled command
  • State machine for seat status: available → reserved → booked

• Scheduled Cleanup:

  • Artisan command seats:cleanup-expired runs periodically
  • Releases expired seat reservations
  • Updates associated booking statuses

3. Real-time Updates

• Livewire Polling:
  • Automatic seat map refresh every 5 seconds
  • Immediate UI feedback for user actions
  • Optimistic updates with rollback on failure

4. Error Handling & Recovery

• Graceful Degradation:
  • Comprehensive error catching and logging
  • User-friendly error messages
  • Automatic reservation cleanup

5. Testing & Simulation

• Concurrent Booking Tests:

  # Simulate concurrent bookings
  php artisan booking:simulate {seatId} --users=100

• Test Coverage:

  • Unit tests for booking service
  • Feature tests for concurrent scenarios
  • Integration tests for booking flow

Future Concurrency Improvements

1. Real-time Updates:

   • Implement WebSocket for instant updates
   • Replace polling with push notifications

2. Rate Limiting:

   • Add rate limiting middleware
   • Configure booking attempt thresholds

3. Advanced Monitoring:

   • Implement deadlock detection
   • Add circuit breaker for external services
   • Enhanced logging and monitoring

Key Technical Decisions

1. Why Livewire?

   • Reduces JavaScript complexity
   • Real-time reactivity without building an API
   • Seamless integration with Laravel

2. Why Soft Deletes?

   • Maintain booking history
   • Enable data recovery
   • Support for analytics and reporting

3. Why Custom Admin Redirection?

   • Better user experience for admin users
   • Clear separation between admin and user interfaces
   • Simplified navigation flow

4. Why 20x20 Seat Limit?

   • Optimal performance for real-time updates
   • Reasonable limit for most venues
   • Prevents potential scaling issues

Future Considerations

1. Scalability Improvements

   • Queue system for high-traffic periods
   • Distributed caching for seat status
   • Horizontal scaling capabilities

2. Feature Enhancements

   • Multiple seating categories
   • Season pass functionality
   • Waiting list system
   • Multi-language support

3. Technical Debt Management

   • Regular dependency updates
   • Code refactoring plan
   • Performance monitoring implementation

Features

• Event Management (CRUD operations)
• Interactive Seat Map Display
• Concurrent Seat Booking System
• Admin Panel
• High Concurrency Safety

Tech Stack

• Backend Framework: Laravel 12.0
• Frontend Framework: Livewire 3.6
• UI Components: Livewire Flux 2.1
• CSS Framework: TailwindCSS 3.x
• JavaScript: AlpineJS 3.x
• Database: MySQL
• Cache: Redis (for session and cache)

Key Packages

{
    "php": "^8.2",
    "laravel/framework": "^12.0",
    "laravel/tinker": "^2.10.1",
    "livewire/flux": "^2.1.1",
    "livewire/livewire": "^3.6",
    "livewire/volt": "^1.7.0"
}

Setup Instructions

1. Clone the repository:

   git clone git@github.com:blessingk/stagepass.git
   cd stagepass

2. Install PHP dependencies:

   composer install

3. Install Node dependencies:

   npm install

4. Copy .env.example to .env and configure your database:

   cp .env.example .env

5. Generate application key:

   php artisan key:generate

6. Run migrations:

   php artisan migrate --seed

7. Build assets:

   npm run dev

8. Start the server:

   php artisan serve

9. Start the queue worker (in a separate terminal):

   php artisan queue:work

10. Schedule the cleanup command (in a separate terminal):

    php artisan schedule:work

Testing

Run the test suite:

php artisan test

Concurrency Testing

To simulate concurrent booking attempts:

php artisan booking:simulate {seatId} --users=100

This command simulates multiple users attempting to book the same seat simultaneously.

Database Schema

Events Table

• id
• name
• description
• date
• venue
• rows
• columns
• status (draft, published, cancelled)
• created_at
• updated_at
• deleted_at

Seats Table

• id
• event_id
• row
• column
• status (available, reserved, booked)
• reservation_expires_at
• created_at
• updated_at
• deleted_at

Bookings Table

• id
• user_id
• event_id
• seat_id
• status (pending, confirmed, cancelled)
• total_amount
• payment_status
• payment_method
• created_at
• updated_at
• deleted_at

Contributing

Please read CONTRIBUTING.md for details on our code of conduct and the process for submitting pull requests.

License

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