They told us "make it do what it always did, but better." They told us to use the newest processes, a new build setup, a new design, a new architecture. It seemed impossible, and for quite a while, we didn't think we would get it done. And then, we did.

My team recently completed a massive rewrite of a project that was more than 10 years old. In just over a year, we changed almost everything: the architecture, the logging process, the design, even the build and deployment setup. About the only thing that remained the same was our development framework. But now twenty thousand people use our rewritten app every day. Was this our best idea? Maybe not! But it is running in prod right now, and running well.

Rewrites are a huge undertaking, one that comes with distinct and potentially expensive tradeoffs. We ran into many of these issues, and I believe that our stories from how we dealt with them can server as an example for other teams. Come along as I present some of the data, successes, failures, and lessons learned by me and my team when we rebuilt a massive project from the ground up.