Node.js is a JavaScript runtime built on Chrome's V8 engine that allows you to run JavaScript on the server-side, enabling development of scalable network applications.

npm (Node Package Manager) is the default package manager for Node.js, allowing developers to install, manage, and publish JavaScript packages and dependencies.

What is middleware in Express?

Middleware functions in Express are functions that have access to request and response objects, can modify them, end the request-response cycle, or pass control to next middleware.

Node.js Interview Questions

121. What are advanced stream internals in Node.js?

122. How does stream backpressure propagate internally?

123. What happens when stream consumers are slower than producers?

124. How would you debug stream memory pressure?

125. What are highWaterMark tuning strategies?

126. How do transform streams affect throughput?

127. What are object-mode stream tradeoffs?

128. How do stream pipelines improve reliability?

129. How would you process terabyte-scale files in Node.js?

130. What are advanced memory-leak patterns in Node.js applications?