PureCode Software Interview Question

SQL: What is the difference between INNER JOIN and LEFT JOIN? Explain the concept of database normalization and its different forms. How would you optimize a slow-performing SQL query? What are indexes in SQL, and why are they important? Can you explain the ACID properties of database transactions? MongoDB: What is the difference between a document and a collection in MongoDB? How does MongoDB ensure high availability and redundancy? Explain the Map-Reduce function in MongoDB. What is sharding in MongoDB, and when would you use it? How does MongoDB handle transactions? React: What are the key differences between functional and class components in React? Explain the concept of state and props in React. What is JSX, and why is it used in React? How would you manage global state in a React application? Can you explain the purpose of React Router and how it works?