Two ways to learn about events
When your system needs to know about events happening in another system, say, a payment completed, there are two main approaches: webhooks, where the other system notifies you by calling your endpoint when something happens, and polling, where you repeatedly ask the other system whether anything new has occurred. Both are common in integrations, with different trade-offs in latency, efficiency, and reliability. Choosing the right one depends on your needs and what the other system supports.
How webhooks work
With webhooks, you provide an endpoint, and the other system sends it a message whenever a relevant event occurs. This is efficient and low-latency: you learn about events almost immediately, without constantly asking. The trade-off is that you must run a reliable endpoint to receive them, handle security (verifying the messages are genuine), and cope with delivery issues. Webhooks are ideal when you want prompt notification and the source supports them.
How polling works
With polling, your system periodically asks the other system for new events or data. It is simpler to implement, you control the schedule, and it works even when the other system cannot push to you. The downsides are latency, you only learn about events at your next poll, and efficiency, you make many requests, most of which may find nothing new. Polling suits cases where near-real-time updates are not essential or webhooks are unavailable.
Reliability concerns
Reliable integrations must handle imperfect delivery. Webhooks can be missed if your endpoint is down, and may be retried, duplicated, or arrive out of order, so you need to verify their authenticity with signatures and handle retries and ordering. Polling can miss nothing if done carefully but must track what it has already seen. Both approaches require thinking about delivery guarantees, what happens when a message is lost, duplicated, or delayed, to be truly reliable.
Idempotent handlers and recovery
A key practice for webhooks is making your handler idempotent: processing the same event twice should not cause duplicate effects, since webhooks can be delivered more than once. Also plan recovery from missed events, for example by periodically reconciling with the source (a bit of polling as a backstop) to catch anything missed. Combining a prompt webhook with a reconciliation safety net gives both low latency and reliability, which is often the best of both worlds.
The bottom line
Webhooks notify you promptly and efficiently but require a reliable, secure endpoint and handling of retries, duplicates, and ordering; polling is simpler and works without push support but adds latency and wasted requests. For reliable integrations, make webhook handlers idempotent and add reconciliation to recover missed events. Understanding the trade-offs helps you choose, or combine, the right approach for your integration.
Related on Skillo
See also: What is a webhook? Explained, What is idempotency? Explained.
Sources
Published date reflects the original event date (2026-10-23). This article is original Skillo editorial written from the sources above; facts were verified in September 2026.
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