Create an API gateway that acts as a single entry point for multiple backend services, handling routing, authentication, request aggregation, and load balancing.

Project Checklist

• Create routing system to forward requests to appropriate services
• Implement authentication middleware
• Add request/response transformation
• Create service discovery mechanism
• Implement request aggregation for multiple service calls
• Add error handling and fallback mechanisms

Bonus Project Checklist Items

• Implement load balancing across service instances
• Add caching layer for frequently accessed data
• Create API versioning support
• Implement circuit breaker pattern
• Add request/response logging and monitoring
• Create API documentation endpoint

Inspiration (Any companies/libraries similar)

• Kong
• AWS API Gateway
• Zuul

Hint/Code snippet to start

const services = {
  users: 'http://user-service:3001',
  products: 'http://product-service:3002',
  orders: 'http://order-service:3003'
};

app.use('/api/*', authenticate);

app.get('/api/users/:id', async (req, res) => {
  const response = await fetch(`${services.users}/users/${req.params.id}`);
  res.json(await response.json());
});

app.get('/api/user-orders/:userId', async (req, res) => {
  const [user, orders] = await Promise.all([
    fetch(`${services.users}/users/${req.params.userId}`),
    fetch(`${services.orders}/orders?userId=${req.params.userId}`)
  ]);
  res.json({ user: await user.json(), orders: await orders.json() });
});