MongoDB Cloud Deployment - High TTFB

I am building a mobile only application in Node.js + MongoDB. I have deployed my server in the AWS AP-Southeast-1 Region.

Since I am new to MongoDB, I am leveraging cloud hosting services like MongoLabs, Compose.IO, MongoDirector (testing a few out). Now, these cloud hosting platforms are deploying my database in either of the AWS AP-Southeast-2 OR US-East-1 Region due to unavailability of Shared hosting in the Southeast-1 Region.

While testing my APIs, I saw a alarmingly high latency in the form of TTFB (Time to First Byte) of ~ 1-1.5seconds. Is this because of the server & database hosted in different regions? Apart from this, my queries are relatively taking less time.

Awaiting a reply as we're soon to goto Production.