Interview Questions Backend Developer

//Nodejs Questions link: https://www.geeksforgeeks.org/node-js/node-interview-questions-and-answers/
What is Node.js?
What is the difference between Node.js and JavaScript?
Is Node.js single-threaded?
What kind of API function is supported by Node.js?
What is a module in Node.js?
What is npm and its advantages?
What is middleware?
How does Node.js handle concurrency despite being single-threaded?
What is control flow in Node.js?
What do you mean by event loop in Node.js?
What are the main disadvantages of Node.js?
What is REPL in Node.js?
How to import a module in Node.js?
What is the difference between Node.js and AJAX?
What is package.json in Node.js?
What is the most popular Node.js framework used these days?
What are promises in Node.js?
What is event-driven progamming in Node.js?
What is buffer in Node.js?
What are streams in Node.js?
Explain crypto module in Node.js.
What is callback hell?
Explain the use of timers module in Node.js.
What is the difference between setImmediate() and process.nextTick() methods?
What is the difference between setTimeout() and setImmediate() method?
What is the difference between spawn() and fork() method?
Explain the use of passport module in Node.js.
What is fork in Node.js
What are the three methods to avoid callback hell?
What is body-parser in Node.js?
What is CORS in Node.js?
Explain the tls module in Node.js.
What is a cluster in Node.js?
How to manage sessions in Node.js?
Explain the types of streams in Node.js.
How can we implement authentication and authorization in Node.js?
Explain the packages used for file uploading in Node.js.
How to handle database connection in Node.js?
How to read command line arguments in Node.js?
What are child processes in Node.js?
Difference Between Restfful and Graphql API?

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Explain what an API endpoint is.
Can you explain the difference between SQL and NoSQL databases?
What is a RESTful API, and what are its core principles?
Can you describe a typical HTTP request/response cycle?
How would you handle file uploads in a web application?
What kind of tests would you write for a new API endpoint?
How do you approach API versioning in your projects?
How do you protect a server from SQL injection attacks?
Explain the concept of statelessness in HTTP and how it impacts backend services.
What is containerization, and how does it benefit backend development?
What measures would you take to secure a newly developed API?
How would you scale a backend application during a traffic surge?
What tools and techniques do you use for debugging a backend application?
How do you ensure your backend code is maintainable and easy to understand?

🟡 Intermediate-Level Questions

Describe how you would implement a full-text search in a database.
How would you approach batch processing in a data-heavy backend application?
Can you explain the use and benefits of a message queue in a distributed system?
What strategies would you use to manage database connections in a high-load scenario?
How would you set up a continuous integration/continuous deployment (CI/CD) pipeline for backend services?
Can you describe a distributed caching strategy for a high-availability application?
What methods can you use for managing background tasks in your applications?
How do you handle data encryption and decryption in a privacy-focused application?
What are webhooks and how have you implemented them in past projects?
What considerations must be taken into account for GDPR compliance in a backend system?
Explain how you would deal with long-running processes in web requests.
Discuss the implementation of rate limiting to protect APIs from abuse.
How do you instrument and monitor the performance of backend applications?
What are microservices, and how would you decompose a monolith into microservices?
How have you managed API dependencies in backend systems?
Describe the concept of eventual consistency and its implications in backend systems.
What is a reverse proxy, and how is it useful in backend development?
How would you handle session state in a load-balanced application environment?

🔴 Advanced-Level Questions

What is database replication, and how can it be used for fault tolerance?
Describe the use of blue-green deployment strategy in backend services.
Can you explain the consistency models in distributed databases (e.g., CAP theorem)?
How do you manage schema migrations in a continuous delivery environment?
What strategies exist for handling idempotency in REST API design?
Describe the implementation of a single sign-on (SSO) solution.
Explain how you would develop a backend system for handling IoT device data streams.
How would you architect a backend to support real-time data synchronization across devices?
Discuss the benefits and drawbacks of microservice architectures in backend systems.
How would you approach load testing a backend API?
Describe how you would implement a server-side cache eviction strategy.
What are correlation IDs, and how can they be used for tracing requests across services?
Explain the difference between optimistic and pessimistic locking and when to use each.
What methods would you use to prevent deadlocks in database transactions?
How would you secure inter-service communication in a microservices architecture?
Discuss techniques for preventing and detecting data anomalies in large-scale systems.
Describe the process of creating a global, high-availability data storage solution for a multinational application.