Cache Invalidation for Updated PDFs

Current Behavior:
When a user uploads a new version of a PDF file to CloudPDF, the cache retains the old version, causing the outdated file to be served to users for a period of time, sometimes up to 15 minutes.

Expected Behavior: When a user uploads a new version of a PDF file, the cache should be invalidated immediately, ensuring that users are served the updated version of the file without delay.

Steps to Reproduce:

1. Upload a PDF file (Version 1) to CloudPDF.

2. Access the PDF file using a unique URL generated by CloudPDF.

3. Upload a new version (Version 2) of the same PDF file to CloudPDF.

4. Access the PDF file using the same unique URL.

5. Notice that the old version (Version 1) is still being served for up to 15 minutes before the new version (Version 2) is displayed.
   

Suggested Solution: Please implement a cache invalidation mechanism that is triggered upon the upload of a new version of a PDF file. This will ensure that the cache is cleared, and the updated file is served to users immediately.

Impact: This issue has a significant impact on the user experience, especially in scenarios where the PDF files contain time-sensitive or frequently updated information.