Push vs Pull Ingestion

The source sending data to you vs you fetching it.

Also known as: push ingestion, pull ingestion, push vs pull, webhook vs polling ingestion

Who starts the data transfer: you fetch it (pull), or the source sends it (push)?

	Pull	Push
How	Your job queries a database, calls an API or reads a file on a schedule	The source calls your endpoint, publishes to a stream, or drops files for you
Who controls timing	You	The source
Freshness	At best your polling interval	Near real time
Load on the source	You create it (polling cost), but you control it	The source decides what to send
Failure handling	Easy: you just retry the pull	The sender must retry, so you need to be reachable and idempotent
Examples	Nightly database extract, REST API polling, SFTP fetch	Webhooks, event streams, a partner dropping files into your bucket

Pull:  [ your job ] ──"anything new since 10:00?"──► [ source ] ──► data
Push:  [ source ] ──"order 917 was paid!"──► [ your endpoint / queue ]

Pull: strengths and costs

Control: you choose when, how much and how fast, and can throttle to protect the source.
Simple recovery: if you missed something, pull it again (with a high-water mark or a date range).
Wasteful for rarely changing data (many polls return nothing), and limited freshness.
Rate limits and API quotas apply (API ingestion).

Push: strengths and costs

Low latency and no wasted polling.
Needs an always-available receiver. If you’re down, the sender may drop events, retry for a limited time, or queue them. Put a durable buffer (queue or stream) at the front.
Receivers must be idempotent: retries cause duplicates (idempotent consumers).
Security: authenticate the sender (signatures on webhooks, mutual TLS, tokens) and validate payloads.
Ordering and loss aren’t guaranteed. Provide a way to reconcile (periodic pulls to fill gaps).
Spikes: a burst of pushes can overwhelm you. A queue absorbs it (message queues).

@app.post("/webhooks/payments")
def receive(request):
    verify_signature(request)                 # authenticate the sender
    queue.send(request.body)                  # buffer durably, return quickly
    return "", 202                            # acknowledge fast; process asynchronously

Choosing

You need freshness, and the source supports it: push (webhooks, streams, change data capture).
The source only offers an API or database, or you want control: pull.
Many real pipelines combine them: push for speed, plus a periodic pull to reconcile (webhooks vs polling).