Waiting (TTFB)

[garyfartsalot]

Any way of speeding of the Waiting (TTFB) for my site.
The initial response can take up to 5 seconds.

Server spec
c5.2xlarge     8vCPU   16 GiB   EBS Only   Up to 10 Gigabit Network

[llegrand]

suggest you run some analysis from these two sites--  drill down and see where you are dragging and look into their suggestions.
Load is impacted by lots of things,  what all is needing to load on your home page, the size impact of your images,  apps, etc. 

https://tools.pingdom.com/
https://gtmetrix.com/