Lemnisk Software Engineer - UI interview questions

I recently attended an interview for a React.js Developer role where I performed well in explaining my past projects and demonstrated a solid grasp of core JavaScript and React concepts. I was confident with basic React hooks like useState and useEffect. However, I faced challenges when deeper technical questions were asked—especially around implementing Promises, understanding advanced hook use cases, and explaining class components with lifecycle methods. This experience highlighted the importance of mastering both fundamentals and advanced topics, especially for optimizing and debugging real-world applications. It reminded me that while it's okay to look things up, key concepts should be readily accessible in a developer's mind.