Top Questions for Senior FullStack Developer Interviews: Ace Your Next Interview

Introduction

Preparing for a Senior FullStack Developer interview can be challenging, especially when you’re not sure what questions to expect. In this article, we will cover the top questions that are commonly asked during Senior FullStack Developer interviews, along with code examples and explanations to help you ace your next interview.

1. What is the difference between a monolithic and microservices architecture?

A monolithic architecture is a single, self-contained application where all components are interconnected and dependent on each other. In contrast, a microservices architecture consists of multiple, independent services that communicate with each other through APIs. Each service is responsible for a specific functionality and can be developed, deployed, and scaled independently.

2. Explain the concept of event-driven programming.

Event-driven programming is a programming paradigm where the flow of the program is determined by events, such as user actions, messages from other programs, or system events. In this approach, the program reacts to events by executing the appropriate event handler, which is a function or method that is triggered when a specific event occurs.

document.querySelector('button').addEventListener('click', function() {
  console.log('Button clicked!');});

3. What is the difference between SQL and NoSQL databases?

SQL databases are relational databases that use Structured Query Language (SQL) for defining and manipulating data. They are based on a schema, which defines the structure of the data, and use tables to store data. Examples of SQL databases include MySQL, PostgreSQL, and Oracle.

NoSQL databases, on the other hand, are non-relational databases that do not use SQL. They can store unstructured or semi-structured data and are more flexible in terms of data modeling. Examples of NoSQL databases include MongoDB, Cassandra, and Couchbase.

4. What is the role of middleware in a web application?

Middleware is a layer of software that sits between the application server and the client, handling various tasks such as authentication, logging, caching, and request/response processing. Middleware can be used to modify or extend the functionality of a web application without changing the core application code.

const express = require('express');
const app = express();

app.use((req, res, next) => {
  console.log('Middleware executed');
  next();});

app.get('/', (req, res) => {
  res.send('Hello, World!');});

app.listen(3000);

5. Explain the concept of Promises in JavaScript.

A Promise is a JavaScript object that represents the eventual completion (or failure) of an asynchronous operation and its resulting value. Promises are used to handle asynchronous operations, such as fetching data from an API, in a more manageable and readable way compared to using callbacks.

const fetchData = () => {
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      resolve('Data fetched successfully');
    }, 2000);
  });};

fetchData().then((data) => {
  console.log(data);}).catch((error) => {
  console.error(error);});