In a past life, I led the migration from datacenter-hosted infra to AWS, and the net result was that we were able to actually increase the size of our infra to

In a past life, I led the migration from datacenter-hosted infra to AWS, and the net result was that we were able to actually increase the size of our infra to support full geo-redundancy, but pay ~40% less to do so. Our app usage had a massive range of requests per second from single digits during off hours to many hundreds during peak hours. By modeling our usage, we were able to combine reserved capacity with appropriate scaling to manage our costs. Since our customers were primarily on mobile, we'd already invested heavily in minimizing egress traffic. Finally, making full use of many of the management tools aved labor costs, so a smaller operations team could support the business.