Here is explantation for each folder and what you can delete to reduce the size.
DeviceSupport - You can keep the simulator which log's you may need in future. It's symbolicate crash logs for different device/iOS.
Delete this folder after every few days interval. Most of the time, it occupy huge space!
~/Library/Developer/Xcode/DerivedData
All your targets are kept in the archived form in Archives folder. Before you decide to delete contents of this folder, here is a warning - if you want to be able to debug deployed versions of your App, you shouldn’t delete the archives. Xcode will manage of archives and creates new file when new build is archived.
~/Library/Developer/Xcode/Archives
~/Library/Developer/Xcode/iOS DeviceSupport
~/Library/Developer/CoreSimulator (Here's a handy shell command for step 5: xcrun simctl delete unavailable)
~/Library/Caches/com.apple.dt.Xcode
https://stackoverflow.com/questions/39481549/what-can-i-delete-from-library-developer-xcode-folder