This page list down free quizzes (questions and answers) in some of the following areas:
- Javascript (Angular/AngularJS, ReactJS, Javascript etc)
- Java & related frameworks (Spring etc)
- ORM frameworks such as Hibernate
- NoSQL databases such as MongoDB, CouchDB
- Databases such as Oracle, MySQL
- Data Science (Machine Learning, Probability and Statistics etc)
- Cloud computing platforms (AWS, Azure, Google Cloud etc.)
- Certification tests
I found it very helpful. However the differences are not too understandable for me