REST Polling vs Webhooks, When Each Wins

Short answer, latency need decides #

Poll a REST resource when freshness can wait minutes or hours, or when scale stays small enough that periodic GET requests are cheap and obvious.

Accept webhooks when an external system must notify you within seconds: payment completed, subscription changed, file ready, provisioning finished. Webhooks push events instead of making you ask repeatedly.

One metaphor carries the post, so here it is. Polling is checking the mailbox: you walk out on your schedule, look inside, walk back. Webhooks are the doorbell: the visitor announces arrival and you answer. Mailbox checks never miss because the doorbell broke. Doorbells never make you walk out in the rain every five minutes. Different timing problems, different tools.

Decision rule: slow-changing reads and simple clients point to polling. Time-sensitive external lifecycle events point to webhooks, but only with verification, retries, and idempotency implemented. A doorbell with no one home is just noise.

How do polling and webhooks differ operationally? #

REST polling follows resource design: stable URLs, correct methods, pagination or cursors, conditional requests, explicit versioning. The client controls timing, which makes failures easy to reason about and replay. Nothing happened? Poll again. Server hiccup? Back off and retry. The state machine fits in your head.

Webhook delivery inverts control: the provider calls your endpoint when something happens. You gain speed and efficiency but inherit distributed-systems chores: delivery attempts, ordering, duplicates, version changes, endpoint availability. Stripe's webhooks docs show the full shape of doing this right: publicly reachable HTTPS endpoints, signature verification with signing secrets, fast 2xx responses before complex logic, async handling, and retries with backoff over days. Paddle frames webhooks the same way at its core: notifications for events in its system, delivered to your URL.

Payments illustrate the split. Polling a transaction status reconciles eventually and simply. Granting entitlement right after checkout demands a webhook path with durable state updates, because the user is staring at the screen waiting for access. Speed has a user on the other end. Polling has a cron job.

How do polling and webhooks compare? #

Neither is modern or legacy. Mailboxes are not legacy. Doorbells are not innovation. They solve different timing problems, and mature systems use both without embarrassment.

Which design rules prevent outages? #

Design REST resources for pollers. Nouns for resources, stable identifiers, cursor pagination for large lists, filters for time ranges. Return cache validators and last-modified signals so pollers skip unchanged work. A poller that can ask "anything new since this cursor" is cheap. One that refetches the world is a self-inflicted load test.

Expect at-least-once webhook delivery. Acknowledge fast with 2xx, enqueue slow work, process asynchronously. Stripe is explicit: return success before complex logic or risk timeouts and duplicate deliveries. Persist each delivery attempt with event ID, type, and processing result so retries stay observable instead of mysterious.

Build idempotency and ordering tolerance into every handler. The same event may arrive twice or out of order, and Stripe documents both: no guaranteed ordering, possible duplicates. Key handlers on stable event IDs, check durable state before applying side effects, and design transitions like pending to active so replays land safely. Log processed event IDs and skip the seen ones. Duplicates become no-ops instead of double charges.

Version REST paths or headers and webhook payloads explicitly. When a provider changes shape, old handlers keep working while new ones roll out. Log the received version with every delivery attempt so debugging starts from facts. Version drift without logs is archaeology.

Respect rate limits on both paths. On HTTP 429, honor Retry-After, apply exponential backoff with jitter, reduce concurrency, and shed low-priority polls first. Never retry payment webhooks or billing polls in a tight loop. Aggressive retries during an incident turn your integration into part of the incident.

// Webhook handler skeleton: verify, acknowledge, queue
export async function POST(req: Request) {
  const signature = req.headers.get('provider-signature');
  const rawBody = await req.text();

  if (!verifySignature(rawBody, signature)) {
    return new Response('Bad signature', { status: 400 });
  }

  const event = JSON.parse(rawBody);

  if (await alreadyProcessed(event.id)) {
    return new Response('OK', { status: 200 });
  }

  await enqueue(event); // slow work happens off-request
  return new Response('OK', { status: 200 });
}

Verification first, dedupe second, queue third, respond fast always. The slow work, provisioning, emails, entitlements, runs off-request where timeouts cannot reach it.

When should you poll by default and when should you push? #

Default to REST polling when data changes slowly, volumes stay low, or no webhook exists. Simpler to test, monitor, and recover. The mailbox always works.

Choose webhooks when the product needs immediate reaction: unlock features on payment, provision on signup, sync on external state change. Treat the endpoint as critical infrastructure with signature verification, queues, idempotent handlers, and alerting on failed delivery attempts.

Many robust systems run both: webhooks for speed, nightly polling for reconciliation. The doorbell announces visitors. The mailbox check catches the one day the bell wire snapped. Reconciliation jobs also heal the silent failures no alert caught: events dropped before your endpoint existed, payloads from before a handler deploy, state changed by admin tools outside the event flow. Speed plus a backstop beats either alone, and the backstop is a cron job you will never regret.

See how BYOB handles payment webhooks

What are the trade-offs? #

Polling is boring in the best way. Webhooks are fast at the price of operational discipline.

Webhooks demand signature verification, fast acknowledgement, queues, idempotent handlers, and alerting, as the BYOB payments path shows (https://byob.studio/blog/byob-paddle-payments). Poll by default when data changes slowly or no webhook exists. Add push when the product must react now, and keep both when correctness matters.

Who this is for (and who should skip it) #

This guide helps builders choosing between polling and webhooks where latency, ordering, and retries matter. If you need real time lifecycle events but you also need to survive redelivery, the decision rules here help.

Skip webhooks when polling already meets latency and the consumer can tolerate periodic checks. Polling stays simple and retry free until near real time need forces a push path.

• Best for developers choosing polling for slow reads and webhooks for instant lifecycle events.
• Best for startups adding signature checks, retries, and idempotency to push endpoints.
• Best for freelancers wiring payment or provisioning callbacks without outage-prone handlers.

What we learned building this #

BYOB handles webhooks for billing and app events with fast ack plus queued work and handlers keyed by event id that stay idempotent, as described in the BYOB webhook retry runbook and the Paddle webhooks overview linked there. That shape keeps delivery at least once but processing exactly once. Polling remains the fallback for reconciliation, and live pages at https://byob.studio/blog/byob-paddle-payments and https://byob.studio/blog/byob-deployment-pipeline-infrastructure return 200 and show the same queued and retry aware wiring.