REST's request-response model fails for real-time needs like chat or live stock prices. Developers have two main options: WebSockets for full-duplex communication and Server-Sent Events (SSE) for server-to-client streaming. The choice depends on whether you need two-way messaging or just server pushes.

WebSockets maintain a persistent connection, allowing either side to send data anytime. This makes them ideal for chat apps, multiplayer games, and collaborative editing tools. However, they require manual reconnection handling and can be blocked by some proxies, adding complexity to your server infrastructure.

SSE operates over standard HTTP, providing automatic reconnection and broader proxy compatibility. It's perfect for notifications, dashboards, and activity feeds where users primarily receive updates. For many applications, combining SSE for incoming data with REST for client actions offers a simpler alternative to full WebSockets.