61. Route 53 Latency Routing Policy

Allows you to route traffic based on the lowest network latency for end user (i.e which region will give them the fastest response time). To use latency based routing, we create a latency resource record set for EC2 (or ELB) resource in each region that hosts our website. When Route 53 receives a query for our site, it selects the latency resource record set for the region that gives the the user the lowest latency. Route 53 then responds with the value associated with that resource record set.
User >> Make a request to Route 53 >> Route 53 is going to look at the different response times from different regions. Suppose a user get 55 milliseconds response time from EU-WEST-2 whereas user get 300 milli seconds response time from AP-SOUTHEAST-2. Its essentially going to send the traffic to the EU West as it has much lower latency.