Sooner or later every CRM integration has to answer one question: how does the other system find out that something changed? A deal moved to “won.” A contact updated their email. A new lead arrived. There are two basic answers, and picking the wrong one produces either stale data or a pile of wasted API calls.

The answers are polling and webhooks. Neither is better in general. Understanding how each fails is what lets you choose.

Polling: Ask on a Schedule

With polling, your integration calls the CRM’s API at intervals and asks what has changed since last time. Typically it keeps a marker, such as the time of the last successful run, and requests records modified after that marker.

Strengths: it is simple to build and reason about. You control the pace. If your system is down for an hour, it catches up on its next successful run, since the changes are still sitting in the CRM. It works behind firewalls with no inbound connection needed.

Weaknesses: there is always a delay equal to the polling interval. Poll often and you burn through API allowances, since most calls return nothing new. Poll rarely and the data lags. It can also miss changes if your marker logic is careless, for instance if two records share the same modified timestamp and you only ask for strictly later ones.

Webhooks: Be Told When It Happens

With a webhook, you register a URL and the CRM sends an HTTP request to it when a chosen event occurs. Your system reacts immediately.

Strengths: near real-time updates, and calls happen only when something changed, which is efficient.

Weaknesses: you now run a public endpoint that must be available, secured and fast. If your endpoint is down when the CRM sends an event, whether the event is retried, how often and for how long depends on the vendor, so check the current documentation. Events can arrive more than once, out of order, or in bursts. And some payloads carry only an identifier, so you still make an API call to fetch the details.

The Practical Differences

Factor	Polling	Webhooks
Latency	Up to one interval	Typically seconds
API usage	Constant, mostly empty calls	Only on change, plus lookups
Build effort	Lower	Higher: endpoint, security, retries
Missed-event risk	Low if the marker is sound	Depends on vendor retry behaviour
Network needs	Outbound only	Publicly reachable endpoint
Ordering	You control it	Not guaranteed
Best for	Batch syncs, reporting, tolerant data	Time-sensitive actions, notifications

Choosing for Your Use Case

Ask how long the delay can be before someone notices. A nightly export to a data warehouse does not need real-time events, and polling or a scheduled bulk export is simpler and cheaper. A rule that alerts a rep within a minute when a hot lead fills a form needs the immediacy of a webhook.

Also ask how bad a missed event is. If losing one update leaves a customer record wrong for weeks, you need something that reconciles. Many robust designs use both: webhooks for speed, plus a periodic poll that sweeps for anything missed. That sweep is cheap insurance.

Design Rules That Prevent Pain

Make handlers idempotent. Process the same event twice and get the same result. Store an event ID or the record’s version and ignore repeats. Duplicate delivery is a normal condition, not an edge case.

Acknowledge fast, process later. Return a success response quickly and push the work to a queue. Long processing inside the request invites timeouts, and a timeout looks like a failure to the sender, which may then retry.

Verify the sender. Check the signature or shared secret the vendor provides, if any, so strangers cannot post fake events to your endpoint. Never trust the payload blindly for sensitive actions; re-fetch the record from the API when it matters.

Don’t assume order. An “updated” event can arrive before the “created” one. Use timestamps or version numbers to decide which state is newer, and fetch the current record when unsure.

Respect rate limits. A bulk import in the CRM can fire thousands of events at once. Queue and throttle so your downstream systems are not overwhelmed. Check the vendor’s current documentation for API limits rather than assuming.

Log what you receive and what you did. When someone says a record did not sync, you want to find the event and see what happened to it.

A Hypothetical Example

A team wants to create a project in a delivery tool when a deal closes. They start with polling every few minutes, which works but occasionally creates two projects when a deal is edited twice in one window. Switching to a webhook gives immediate creation. They add an idempotency check keyed on the deal ID so a repeat event does nothing, and a nightly poll that lists recently closed deals and creates any missing projects.

The nightly sweep catches the one evening their endpoint was down during a deployment. Neither mechanism alone would have been as reliable as the pair.

When Neither Is Right

If you are moving large volumes, such as an initial load or a periodic full reconciliation, use the vendor’s bulk export or bulk API where available instead of page-by-page polling. If you have middleware or an iPaaS in place, it may already provide triggers and handle the retries for you. That trades some control for less custom code, which can be sensible.

Frequently Asked Questions

Are webhooks always faster than polling? They are usually quicker to notify, but processing delays, queues and vendor delivery behaviour affect the end result. Measure rather than assume.

What happens if my webhook endpoint is down? It depends on the vendor. Some retry for a period, some do not. Check current documentation and design a reconciliation poll as a backstop.

How often should I poll? As rarely as your use case tolerates, weighed against API allowances. Start with a modest interval and tighten only if people actually notice the lag.

Can I use webhooks without writing code? Often yes through integration platforms that expose triggers. You still need to understand duplicates and ordering.

Do all CRMs support webhooks? Not uniformly, and the event types vary. Check what your platform offers before designing around it.

Next Step

Pick one integration you run today, write down its acceptable delay and what happens if an event is missed, then decide whether it needs a webhook, a poll, or both.