What is the recommended approach to migrate an internal file upload API with a 500-MB limit to App Engine?

The recommended approach to migrate an internal file upload API with a 500-MB limit to App Engine is to change the API to be a multipart file upload API. This method is beneficial because multipart file uploads allow large files to be divided into smaller, manageable parts that can be uploaded independently and in parallel. This is particularly advantageous for situations with stringent file size limitations, as well as for maintaining the integrity of file uploads by allowing for resumable uploads.

Using multipart file uploads also aligns well with the stateless nature of App Engine, where requests and responses are typically short-lived and transient. It allows efficient error handling; if an upload fails, only the parts that were not uploaded need to be retried rather than resending the entire file.

In contrast, other options such as using FTP or CPanel would not integrate well with the App Engine environment, which is designed for applications that run in a serverless environment with no access to traditional file systems. These methods are not optimal for cloud-native applications, especially within the guidelines and best practices established by Google Cloud. Additionally, employing signed URLs can be a useful strategy for granting temporary access to an object in storage, but it doesn't directly address the need to change the API structure to accommodate larger file sizes