A common recurring pattern with software development is the need to update our codebase to use the latest and greatest SDKs, whether it be the Swift language or 3rd party libraries. You can get away with delaying the migration process for a year or even two years, but you'll be missing out on all the new features and bug fixes available. It's always my recommendation to update Swift and other dependencies as much as possible without disrupting the development cycle. Today we'll be going through how to update our current project to use Swift 4 and Firebase 4 SDKs. Make sure you've properly backed up your project in a separate folder or in Git somewhere before you proceed.