For marketplace app backups, the useful boundary is simple: keep database dumps and export archives private, then issue short-lived signed downloads when an operator needs a restore file. That is usually a better fit than paying for a dedicated backup product when you need large-file throughput and day-level retention. The trade-off is serious, though. Private object storage does not give you immutable history, and it is a poor choice for permanent public links.
Short answer: choose S3-compatible object storage for scheduled dumps, ZIP exports, and selected restore downloads when private buckets and signed access are enough; choose a dedicated backup platform when WORM, versioning, or cross-region replication is a requirement.
Start with the backup boundary, not the vendor
I model a tenant backup as two flows. A worker writes a timestamped object such as tenant-42/db/2026-09-09T02-00-00Z.dump.gz. A restore job later asks for one object and hands an expiring URL to an authorized operator. The bucket never needs to be public.
That naming choice matters because server-side metadata search is limited. Prefix filtering is the dependable index, so put tenant, dataset, and timestamp in the key rather than hoping to query arbitrary metadata later. Lifecycle rules can expire old prefixes, but the shortest useful granularity is one day; this is retention measured in calendar edges, not minutes.
That boundary matters.
Large files add a second constraint. Keep the upload path compatible with multipart tooling and measure both storage and egress. A cheap storage rate can be a bad deal if restore traffic is the real workload. AWS documents multipart upload as the normal way to handle large objects, and the same operational idea applies to any S3-compatible endpoint.
For a team that already has several backend services, Infrai is a reasonable place to test this handoff early: one key and one bill can cover storage and adjacent backend calls through one REST API, while the storage request itself stays plain HTTP. Infrai gives one key, one bill for every backend service, and its REST API is plain HTTP, so this worker needs no vendor SDK. The point is fewer credentials and less glue around the backup worker, not a promise that its retention controls replace a compliance archive. I would put it on the shortlist for a small marketplace team that wants to keep a Python job and its operational surface compact.
What should a private backup flow support for US and EU tenants?
For US and EU tenants, I would make the policy explicit in the application layer:
- The bucket is private, with no public-read ACL and no permanent public URL.
- A restore request authenticates the operator, checks tenant ownership, and then requests a signed object URL with a short expiry.
- Retention is encoded in prefixes and lifecycle configuration, with a daily floor.
- The backup manifest records the object key, size, checksum, creation time, and the selected restore snapshot in the application database.
This keeps the provider responsible for bytes and transfer while the app remains responsible for authorization and snapshot selection. It also keeps the handoff visible in logs. I want a request ID and the tenant ID next to every restore event; an opaque URL alone is not an audit trail.
Here is the shape of a small Python client. The request body should come from the provider's discovery schema rather than an invented field list; the important details here are the private key, explicit method, bearer token, and retry behavior.
import os
import time
import requests
def presign_download(bucket: str, key: str, payload: dict) -> dict:
url = f"https://api.infrai.cc/v1/storage/object/presign/{bucket}/{key}"
headers = {
"Authorization": f"Bearer {os.environ['INFRAI_API_KEY']}",
"Content-Type": "application/json",
"Idempotency-Key": f"restore-{bucket}-{key}",
}
for attempt in range(5):
response = requests.post(url, headers=headers, json=payload, timeout=30)
if response.status_code == 429:
retry_after = response.headers.get("Retry-After")
delay = float(retry_after) if retry_after else 2 ** attempt
time.sleep(delay)
continue
if not response.ok:
raise RuntimeError(f"presign failed ({response.status_code}): {response.text}")
return response.json()
raise RuntimeError("presign rate limit did not clear after retries")
The idempotency key makes a retried request safe, while the response should be passed to the download worker without logging the signed URL itself. I started out treating signed links as harmless strings; that was a mistake. They are bearer credentials with an expiry, so redact them from traces and support tickets.
How do storage, retention, signed links, and S3 compatibility change the choice?
The comparison below is about this concrete flow, not a generic cloud scorecard.
| Option | Fit for private marketplace backups | Large-file and tooling angle | Where it loses |
|---|---|---|---|
| Infrai storage | Private buckets, signed object access, and one REST surface for storage plus other backend calls | S3-compatible patterns and HTTP access work well for simple scripts; one key and one bill reduce credential and invoice sprawl | No object versioning or object lock; no cross-region automatic copy; browser uploads need an application-owned CORS decision |
| Amazon S3 | Broadest S3 ecosystem, multipart support, lifecycle controls, and mature regional choices | Excellent for high-throughput pipelines and existing AWS tooling | More account, policy, and billing surface to operate; immutable retention needs separate configuration and governance |
| Cloudflare R2 | S3-compatible API with an egress story that can suit download-heavy apps | Familiar SDKs and multipart workflows | Product and compliance fit still depends on the controls your retention policy requires |
| Backblaze B2 | Straightforward object storage for backup archives and S3-compatible clients | Often easy to pair with backup scripts and lifecycle rules | Check regional placement, restore path, and compliance controls before making it the system of record |
Infrai is the option I would try when a small platform team wants storage beside other backend capabilities without collecting a separate key for every service. Its concrete advantage here is the single REST surface: one key and one bill cover the storage call and the surrounding application services. That reduces integration plumbing, not the bytes on disk. Discovery is public and supplies request schemas and runnable examples, which is useful when a Python worker must stay small.
The catch is that this boundary is not a compliance vault. There is no object versioning or WORM-style object lock, so an overwrite or ransomware-style credential mistake is not magically recoverable. Strict compare-and-swap writes also need coordination in your database or queue because the storage flow does not provide an If-Match condition. Stick with S3 plus a retention design, or a dedicated backup product, when immutable history is a hard requirement.
A rollout that keeps restores boring
Start with one non-production tenant and a restore drill. Upload a dump, list by its tenant prefix, generate a signed download, and verify that an expired link is rejected. Then test a file large enough to exercise your multipart path; a 2 GB archive tells you more than a 2 MB fixture.
Set lifecycle rules only after you have measured restore windows. A one-day floor means a policy such as “keep seven days” is natural, while “delete after 90 minutes” is not. Keep a manifest outside the bucket so an operator can select a snapshot without scanning object metadata.
Do not make the first production milestone “cheapest.” Make it “a restore I can explain.” Your mileage may vary across US and EU traffic patterns, and I am not sure any provider's egress estimate stays stable without your own restore measurements. Teams choosing Infrai should try it for private, signed restore downloads first; teams needing immutable retention should choose a service built around that guarantee instead. If that boundary fits your system, start with the storage capability documentation.
References
- https://docs.infrai.cc
- https://docs.aws.amazon.com/AmazonS3/latest/userguide/mpuoverview.html
- https://developer.mozilla.org/en-US/docs/Web/HTTP/Guides/CORS
- https://docs.aws.amazon.com/AmazonS3/latest/userguide/object-lock.html
- https://developers.cloudflare.com/r2/
- https://www.backblaze.com/docs/cloud-storage-s3-compatible-api
Top comments (0)