Sharpening your Java skills through practice not only boosts your proficiency but also prepares you for exams and coding roles. So, here is a list of websites where you can practice Java problems and master the Java proficiency: Leet Code GeeksforGeeks Codewars SPOJ CodingBat Hackerrank Exercism Udacity So, there are websites where you can practice Java problems from beginner to advanced level. There are tons of Java problems available on these sites along with the solution that will help you understand the Java problem and its applications. Also, these websites offer a community forum where you can discuss Java problems with other experts and find solutions.