Handle high traffic and connection in Haproxy

As an experienced engineering team we are looking to expand our Haproxy capacity to handle high volumes of traffic in a cost-effective manner. We are expecting a large amount of traffic and do not require a dedicated server since Haproxy is an efficient traffic handler. Additionally, we need our system to be enabled with HTTP protocols.

Server : Ubuntu

Maybe Problem is
-haproxy/nginx open files
-thread limit in kernel

I cant handle more than 4-10k connections.

I can share you the server details for you to check and make a clean install for you.

Looking for someone professional.