Polling vs. Webhooks
Polling and webhooks compared by freshness, infrastructure needs, and failure handling.
Polling and webhooks solve the same integration problem from opposite directions. Polling asks, "has anything changed yet?" Webhooks say, "tell me when it changes." The right choice depends on latency needs, infrastructure constraints, and how much operational complexity each side can absorb.
Polling is straightforward. Your system calls an external API on a schedule and checks for new data. That simplicity is its main advantage. You control the timing, retry policy, backoff behaviour, and authentication from one side only. Polling also works well when the external service cannot call back into your environment because of firewalls, private networks, or compliance boundaries.
The downside is inefficiency. Most poll requests return nothing new, which wastes bandwidth and compute on both sides. Polling also introduces a freshness ceiling. If you poll every five minutes, your data can be nearly five minutes stale by design. Tightening the interval reduces latency but increases load, and aggressive polling can become a scalability problem quickly or run into provider rate limits.
Webhooks invert the model. You expose an endpoint, register it with the provider, and the provider pushes events to you when something meaningful happens. This is better for near-real-time updates such as payment status changes, shipment notifications, or user lifecycle events. It avoids the empty-check problem and reduces average latency dramatically.
But webhooks move complexity into operations. Your endpoint must be internet-reachable, authenticated, and resilient to retries, duplicates, and out-of-order delivery. Providers usually retry when they do not receive a timely success response, so consumers must be idempotent. Signature verification is also essential because anyone can send an HTTP request to a public endpoint unless you validate that it came from the provider.
Neither model guarantees perfection on its own. Polling can miss nothing as long as the source keeps historical state available, but it may be slow. Webhooks are fast, but notifications can fail temporarily due to network issues or endpoint outages. That is why many mature integrations use both: webhooks for low-latency hints, plus periodic polling or reconciliation to repair missed events.
So the decision is less about which method is modern and more about where you want the complexity. Polling concentrates control in the client and spends more resources. Webhooks reduce waste and improve freshness but require a robust receiving system. Choose based on the provider's capabilities, the criticality of timeliness, and whether your application can safely process retries, duplicates, and recovery after missed notifications.