First round is a quick phone interview; don't be fooled, it's not just a behavioral. It starts off with the interviewer telling you about the company, and what they're looking for. First, the interviewer speeds through this and jumps into quick behavioral questions, mostly talking about yourself and your software development journey. After this, you enter a speedy technical challenge about OOP principles. Most of it is university level OOP terms you learn in your first year, I would recommend touching up on these as its not really something you'd remember working in the field, more of a school knowledge. After the technical questions, you get a chance to ask a couple questions of your own