It all depends on the application and the framework you are working on. Is it something proprietary or do you use an already existing framework to build your SaaS platform?
In order to improve Web performance, first of all demand for the application is required to be determined/computed.(X)
Then identify the current status [How much is being supplied now.]. (Y)
Find the difference.You shall get either -tive or Zero or +tive.
D=Y-X
If its Zero, means your demand and supply coincide exactly. But practically its not possible.
If the value is negative, means you over under provisioned the resources. Find the gap and attempt to fill it.
If the value is positive, means you have over provisioned the resources.Attempt to free underutilized resources.
You should be able to do a demand to resource conversion.;means based on the demand, how much resource you required to supply and fulfill the requirement.