I have a data-set of 16 Millions for which I will send the address etc to Google Geocoding API and get the lat-longs. Right now we are making an API request for POI by POI, I'm wondering if we can do bulk /batch request, where in which I send around 500 POIs or so, so that we can save some round-trip time. Please advise.
You can use the Web-Service Geocoding API and call the request via Curl, you'll just need to create an interval for each batch request to reaching the request/100s limit. If the maximum request/100s limit is not enough for your use case, you may file a support case via https://console.cloud.google.com/google/maps-apis/support so the support team can help you give your account more capability to send requests more than the limit.