Reliable File Upload API featuring Validation, Storage, and Secure Access

Create and put into use a secure, scalable API to manage file uploads. The following characteristics ought to be present in the API:

1. Handling File Uploads:
   • Allow uploads of one or more files.
   • Accept common file kinds with adjustable limits, such as documents, PDFs, and photos.
2. Verification:
   • Before processing, check the file’s format, size, and type.
   • Reject harmful or incorrect files with unambiguous error messages.
3. Storage Choices:
   • Save files locally or in cloud storage (such as Azure Blob, AWS S3, or similar).
   • To prevent conflicts, make sure that files are named and organized effectively.
4. Safety:
   • Put authorization and authentication in place for upload and access endpoints.
   • Clean up file names and stop vulnerabilities (such as malware uploads and path traversal).
5. URLs for Secure Access:
   • Create signed or time-limited URLs to access files that have been submitted.
   • Make sure files may only be retrieved by authorized users.
6. Design and Documentation of APIs:
   • Observe RESTful best practices.
   • Incorporate error handling, request/response formats, and explicit endpoint definitions.
   • Give examples of requests and answers.
7. Scalability and Performance:
   • Effectively manage massive file uploads (e.g., chunking if necessary).
   • Make sure the system can accommodate big volumes of storage and significant traffic.

Provide clear, well-organized code with a modular design and adhere to best practices for ease of maintenance and future expansion.