Explain the concept of "event delegation" in JavaScript. How does it improve performance and memory usage in a web application? How would you handle cross-origin resource sharing (CORS) issues in a web application? What are the different approaches for handling CORS in both frontend and backend? In a microservices architecture, how would you manage inter-service communication and ensure data consistency across services? What tools or patterns would you use? Describe the differences between SQL and NoSQL databases. In what scenarios would you choose one over the other, and how would you handle data modeling in both types of databases? How do you optimize a web application for performance? Discuss strategies for frontend, backend, and database optimization. Explain how you would implement authentication and authorization in a web application. What are the differences between sessions and JWT tokens, and how do you handle secure storage and transmission of tokens? Describe the role of containerization in modern web development. How does Docker fit into a full stack development workflow, and what are the advantages of using it? How would you design a RESTful API for a complex application? What are the key principles of REST, and how would you ensure your API is scalable and maintainable? Discuss the concept of state management in frontend frameworks (e.g., React, Vue.js). How would you handle global state in a large-scale application, and what tools or libraries would you use? What are the potential security vulnerabilities in a web application, and how would you mitigate them? Provide examples of common vulnerabilities and explain best practices for securing both frontend and backend components.