There have been several duplicate questions and number of duplicate questions is increasing. So to prevent users from writing more duplicate questions, I suggest to implement real-time suggestions for the questions that are being written like in stackoverflow if possible:
As simply marking questions as duplicate, doesn’t necessarily allow users to check the duplicate question; if they missed a question while browsing, finding a duplicate question as suggestion will more flexibly allow users to review it right before asking another one!!
The same also applies for other categories, for example repetitive bug reports about the
mongodb in past.