OOP organizes code using objects and classes. Know the four key concepts: encapsulation, inheritance, polymorphism, and abstraction.
Be familiar with arrays, linked lists, stacks, queues, trees, and hash tables. Explain when and why you would use them.
Explain how you improve performance by reducing unnecessary operations, choosing better algorithms, and checking time and space complexity.
An API helps different software systems communicate. Understand REST, HTTP methods, status codes, authentication, and error handling.
Explain how you reproduce the issue, check logs, identify the cause, test a solution, and confirm that the problem is fixed.
Review coding concepts, practice problems, and prepare examples from your projects. Clear communication and practical knowledge can make a strong impression.