Real-time features are now expected: live inventory, streaming updates, notifications, and dashboards. The transport choice impacts performance, complexity, and cost.
WebSockets
Best for two-way communication and high-frequency events.
- Pros: bi-directional, low-latency
- Cons: stateful connections, scaling complexity
Server-Sent Events (SSE)
Best for server-to-client updates with simpler infrastructure.
- Pros: simple, works well for streaming updates
- Cons: one-way, requires fallback for some environments
Long polling
Best as a fallback when infrastructure is limited.
- Pros: simplest to implement on top of HTTP
- Cons: higher overhead, less “real-time”
Choose based on message direction, frequency, and operational maturity.