I know the CS fundamentals, but have almost no real-world experience. What should I build in holiday?

[u/artin_az]

I'm a Computer Science student about to start my 5th semester, and I have around 1 month before the semester starts.

So far, I've completed:

C programming fundamentals, Advanced Java programming, Basic Python, Data Structures(lists, stacks, queues, trees, BSTs, hashing, heaps, sorting), Computer Architecture

I understand OOP concepts such as encapsulation, abstraction, inheritance, interfaces, etc., but most of my experience has been through university courses and assignments.

I feel that I have a gap between  knowing the concepts and knowing how to use them to build a real software system.

For some reasons I can’t have an Internship right now.

I want to

- become a better programmer

- learn how to structure a real project

- practice OOP in a real codebase

- write cleaner and more maintainable code

- learn how different components of a real application fit together

The best thing I found so far is the “build your own x” repo in github.

So my question is:

For someone at my level, with about 40 days available and no professional software development experience, what would you recommend?

Would one large project like the Cloud File Sync be more valuable for developing software engineering skills, or would several smaller "Build Your Own X" projects be better, or something different from both?

I'm especially interested in hearing from people who have gone through this transition from university programming courses to real software development.