Pergunta de entrevista da empresa Gray Matrix Solutions

Explain the MERN architecture. How do the components interact? Tests understanding of full-stack flow and how data moves from frontend to backend and database. How would you design a RESTful API using Express and MongoDB? Assesses backend design skills, routing, and database schema design. What are React hooks, and when would you use useEffect vs. useMemo? Evaluates React knowledge, state management, and performance optimization. How do you handle authentication in a MERN stack app? Covers JWT, session vs. token-based auth, and middleware in Node/Express. Describe how you’d implement pagination or infinite scroll in a React frontend. Looks at frontend data handling and user experience optimization. Live coding: Create a basic CRUD API using Express and Mongoose. Tests ability to write backend logic and interact with MongoDB. Live coding: Build a simple to-do app in React. Checks frontend skills, state handling (with or without Redux), and component design. Walk me through a MERN project you’ve built. What challenges did you face? Gauges practical experience, problem-solving, and ownership. How do you ensure performance and scalability in a MERN app? Explores knowledge of caching, indexing, load handling, and frontend optimizations. How do you debug a slow API endpoint or a frontend rendering issue? Reveals approach to performance bottlenecks and use of tools (e.g., Chrome DevTools, Postman, logs).