{
  "id": 15992331,
  "title": "Private Exports: Caching Signed Download Links to Reduce Presign Rate-Limit Requests",
  "url": "https://urgent.news/2026/10/22/private-exports-caching-signed-download-links-to-reduce-presign-rate",
  "topic": "tech",
  "section": "Tech",
  "published": "2026-10-22T03:27:17.000Z",
  "source": {
    "name": "Dev.to",
    "slug": "dev-to",
    "url": "https://dev.to/marcorossi4891/private-exports-caching-signed-download-links-to-reduce-presign-rate-limit-requests-91h"
  },
  "original_language": "en",
  "account": "Fintech firms can store private downloads on object storage, but the rate of signed download links must be managed. To avoid hitting presign rate limits, cache each valid signed link in the backend and reuse it when the same user downloads the same file. Generate a new presign link only when the cache entry expires, using bounded exponential backoff instead of creating a new authorization artifact upon each click. Cache the URLs by tenant, user authorization scope, export job, and object key. Return a cached URL as long as it has a safety margin; otherwise, generate a replacement. Don't rely solely on object keys for caching, as that might cross access boundaries even if the object remains private. The export record should store job state and object key after generation, while the signed URL is just temporary state. A page refresh can reuse the cached link instead of starting a new export or presign call. Determine the expiry margin through load tests considering file sizes and client geography. Always expire the cache before the URL itself. Here's a Python script to fetch signed links without creating new requests or handling responses: import json, os, random, threading, time, urllib.error, urllib.parse, urllib.request. The script defines a RateLimited exception, an API root, an API key, a cache dictionary, a lock dictionary, and a lock guard. It has methods to lock for a cache key, request a signed link, and get a link with proper error handling. If the API returns a 429 status, the script raises a RateLimited exception with the retry-after value if available. If any other 4xx error occurs, it raises a RuntimeError. This approach allows the system to handle rate limits efficiently while providing a smooth user experience.",
  "summary": "Short answer: object storage fits private fintech exports, but large-file throughput depends on keeping page refreshes away from the presign path. Cache each still-valid signed download URL in the backend, preserve the export job and object key, and retry presign generation with bounded exponential backoff instead of signing again on every click. A 4 GB statement archive should spend its time…",
  "key_points": [
    "Store private downloads on object storage, manage signed download link rate.",
    "Cache valid signed links in backend, reuse when same user downloads same file.",
    "Generate new presign link only when cache entry expires, use bounded exponential backoff."
  ],
  "editors_take": "Caching signed links by tenant and authorization scope prevents rate-limit exhaustion and ensures fintech platforms maintain seamless file access without triggering unnecessary authorization requests during repeated user downloads.",
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}