As of now we should have 6 steps/API calls to create an attachment in an activity
1. check the file already existing
2. upload chunk file
3. complete chunk upload
4. create Attachment
5. create attachment version
This approach taking log time to create one attachment.
One of our requirement demands at least 100 to 200 attachments to upload, which taking log time.
So please reduce the steps to create attachments
Customer support service by UserEcho