First Time Byte Isuue

I have developed a php (Code-igniter) Website . I have tested it with webpagetest.org and i got following results

First Byte Time-F
Keep-alive Enabled-A
Compress Transfer-A
Compress Images-C
Cache static content-A
Effective use of CDN-Yes

Url - http://54.88.242.247/marketplace/

First Provide solution for First Byte Time-F .
Please help me to improve site performance.

Thanks
Rohit Ambeldkar

Looks like it’s a VM on AWS so I assume you have root access to the server. You should install something like New Relic which will tell you what the slow parts of your back-end application are (the things you need to fix).

From the outside it is a black box and it could be anything from server config to the application code on the server to external services that it calls out to.