Depending on which companies you interview, you may get questions about OOP design patterns particularly about SOLID principles. To be adequately prepared for these questions, please read the following articles:
Understanding how to apply SOLID principles to your work could be intimidating and awkward in the beginning, but with more practice, you'll get better. For now, focus on the terminologies and understand enough that you can speak these terms during interviews.
You can also read my article: SOLID Principles. Are they as important as they used to be 20 years ago?
Many developers have also mentioned how they were asked questions about factory design pattern vs builder design pattern and when they would use which. To understand what these two design patterns are and when to use which, please read:
In your technical interviews, what other design patterns were asked frequently?