Poka's Angular app was getting pretty large. In fact, it was slowly becoming a problem as it would take an enormous 8 seconds to compile on Google Chrome before it actually ran. That’s 8 seconds of waiting for every user booting the web app. Ahead of Time compilation (AoT) can fix that kind of issue.
Many organizations have large AngularJS 1.x applications deployed to production. These applications may be built by multiple teams from different lines of business. They may use different routers and state management strategies. Rewriting such applications all at once, or big bang migrations, is not just impractical, it is often impossible, and mainly for business reasons. We need to be able to upgrade gradually.