Make it MERN
This runtime allows JS to run outside the browser and powers the backend in a MERN app.
What is Node.js?
This syntax lets you write HTML-like code directly inside JavaScript files.
What is JSX?
This data format is commonly used to send information between client and server.
What is JSON?
Functions in JavaScript can be stored in variables, passed as arguments, or returned from other functions.
What are first-class functions?
This tool helps you inspect network requests, responses, and errors in the browser.
What are browser developer tools?
These 4 database operations form the backbone of most APIs.
What are Create, Read, Update, and Delete (CRUD)?
This hook allows functional components to store and update local state.
What is useState?
This security mechanism controls which domains are allowed to access an API.
What is CORS?
This array method creates a new array containing only elements that pass a test.
What is filter?
This pattern is commonly used to surface backend errors in a React UI without crashing the app.
What is setting an error state and displaying it in the UI?
This Express feature sits between the request and response to handle tasks like auth, logging, or validation.
What is middleware?
This React concept refers to data passed from a parent component that cannot be modified by the child.
What are props?
This Node.js feature enables non-blocking behavior by managing asynchronous tasks.
What is the event loop?
This concept describes an inner function retaining access to variables from its outer scope.
What is a closure?
This middleware is configured when React and Express run on different ports during development.
What is CORS middleware?
This MongoDB library adds schemas, validation, and models on top of a NoSQL database.
What is Mongoose?
This hook is used for side effects like fetching data or subscribing to events.
What is useEffect?
These codes indicate the result of an HTTP request, such as success or failure.
What are HTTP status codes?
This programming principle avoids changing existing data and instead creates new copies.
What is immutability?
This debugging strategy involves checking one layer at a time—UI, network, then server.
What is isolating the problem by layers?
This architectural style uses standard HTTP methods and stateless requests to interact with resources.
What is a REST API?
This lightweight in-memory representation allows React to efficiently update the real DOM.
What is the Virtual DOM?
This Express middleware improves security by setting HTTP headers.
What is Helmet.js?
These are observable changes outside a function’s return value, such as logging or API calls.
What are side effects?
This describes the full lifecycle of a form submission from React state to MongoDB and back.
What is the client–server request/response flow in a MERN app?