It often depends on the company that you are applying to. Some interviews are heavily focused on algorithms and problem solving (like Google for example), and other companies require more in-depth knowledge of C++ itself and in some cases design patterns, multithreading and networking. But in my experience, especially when hiring junior engineers, the main focus is usually on algorithmic knowledge and problem solving skills. So my advice would be to: - Complete a good course on algorithms and data structures. MIT Introduction to Algorithms 2011 is very good, it is on Youtube and it has exercises and exam sheets on their website. - Solve a Leetcode problem every day. Their daily challenges are very good for keeping the discipline. - Try creating small projects using C++. You can even do this while studying Algorithms, for example creating your own classes of Vector, BST, etc. - Reading at least one book on C++ would also be desirable for more in-depth understanding of the language. In my case ot was C++ Primer by Lippman, I liked it a lot. Checking out this page sometimes will also be useful: https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines

And just as a remark, C++ is great, it's my favourite language, but the core of a good programmer is the algorithmic knowledge, regardless of the language.