My first back end deployment & stress testings without NGINX

Challenge
Deploying database and server on AWS.
Using loader.io to do stress testings.

Action
I have completed deploying my backend server along with another instance of database on AWS

I have stress tested using loader.io and here are my first testing results

1000 users per second for 1 minute (for complex query request) (first try)

1000 user per second for 1 minute (for complex query request) (second try)

1000 user per second for 1 minute (for less complex query request)

So I started increasing number of clients.
I tried 5000 clients per second for 1 minutes for less complex query

I also tried same 5000/1 test for complex query

but test was aborted.

Then I tried 2500/1 for complex query

Here is 5000/1 for less complex query

1500/1 for complex query

It seems like failures are happening when it goes over 1000/1 request.

Result
Everything works. But would still need to implement NGINX for higher performance for higher request per second