Resolve issue with React.js with Node.js API performance for making ~500 POST requests

I am looking for a developer with experience in React.js and Node.js to resolve an issue with the performance of our platform (react.js front end, Node.js API). We are currently experiencing slow page load times, primarily due to individual post requests required to be made to generated a signed URL for image delivery. Some pages have up 500 photos, which means 500 POST requests made to server to generate the URL.

Current Performance:
- Page with 500 takes up to 20 seconds to load all photos with signed URLs
A screenshot showing load statistics has been provided and example of queue and stall time has been provided.

Error Messages:
- We are not receiving any specific error messages consistently or sporadically.

Desired Performance:
- We expect the total page load time to no more than 5 seconds.

Possible outcomes:
- Explain how to avoid POST requests being queued
- Potentially consolidating post requests (least preferred)

Skills and Experience required:
- Strong knowledge of React.js and Node.js API
- Experience in optimizing performance for high volume POST requests
- Familiarity with troubleshooting and resolving performance issues
- Ability to analyze and optimize API calls and data handling

If you have the skills and experience necessary to resolve this issue and improve the performance of our system, please submit your proposal.