Intermediate Java Coding Test Creation

I require an experienced Java coder to construct an intermediate level, extensive coding test. The test needs to center around:
- Object Oriented Programming (OOP)
- Data Structures

In addition, I would like the test to challenge on:
- Recursion Problems
- Specific OOP Concepts

The ideal candidate should excel in constructing coding tests, with a firm grasp of OOP, data structures, and recursion. An understanding of varying levels of coding difficulty is instrumental for this project. I'm counting on your knowledge and expertise to craft an informative, approachable yet challenging exercise. Your contribution directly affects testing standard and quality.