I have studied and observed the patterns from the accounts which are already on the top levels. One thing is common among all. They all have solved an adequate amount of problems in their rating domains.
One can set an arbitrary boundary of about 50 questions at each difficulty level. However, this may vary from person to person.
Browser extensions like "CF Analytics" will be useful to get greater insights.
During solving the problems fix time bound to better push limits. Don't wait for things to be finished then you will come and solve more problems. Learning things while solving will give your coding journey better efficiency.
Good Luck and Happy Coding :)
