Jumpstart your future with these full-stack developer interview questions and answers


Rachita Jain


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Today, technology is developing at a rapid rate, and businesses worldwide are using a variety of technologies for their product development and upgradation. This has created a huge demand for Full Stack developers, who possess great command over multiple programming languages. If you aspire to build a career in Full Stack Development, the future is all yours.
If you have an upcoming or approaching interview and you have no idea how to prepare for full-stack developer interview questions and answers, stay hooked.
AllRemote has compiled a list of the top full-stack developer interview questions and answers to help you ace your interview.

Full Stack developer interview questions for freshers

1. Explain the difference between front-end development and back-end development.

This is one of the most asked full-stack developer interview questions and answers. Here’s how to answer-
The website or application's user interface and visual components are designed as part of front-end development. To provide a responsive and engaging user experience, it deals with HTML, CSS, and JavaScript. On the other hand, back-end development concentrates on the server-side logic, database administration, and server architecture needed for the application to run. It consists of databases, frameworks, and programming languages.

2. What are some popular front-end frameworks and libraries you are familiar with?

Some popular front-end frameworks and libraries include React, Angular, Vue.js, jQuery, Bootstrap, and Material-UI. Now this is a subjective full-stack developer interview question. So mention any frameworks or libraries you have worked with and explain your experience.

3. Can you explain the Model-View-Controller (MVC) architecture?

The Model-View-Controller (MVC) is a design pattern commonly used in web development. The MVC model represents the data and business logic, the view is responsible for the presentation and user interface, and the controller handles the interaction between the model and the view. It helps in organizing the codebase and separating concerns.

4. Which language is the most preferred language by full-stack developers?

Programmers who work on full-stack development use a variety of languages. An applicant applying for a full-stack developer position should ideally be fluent in various languages, preferably some for the front-end design and others for the back-end maintenance. All the full Stack developers must have comprehensive knowledge of at least two to three most widely used languages, including Java, Python, Ruby, PHP, C++, etc. because they work with various technologies and applications.

5. What is pair programming?

In pair programming, two programmers collaborate on a single machine. One programmer will operate as the driver who programs during the development process. At the same time, another will be the observer (navigator) who will ensure the code is written correctly, proofread it, and spell-check it while determining where to go next. The driver can change into the observer at any time and vice versa. Pairing, paired programming, or programming in pairs are other names for this practice.

6. What is dependency injection?

Dependency IoC is carried out using the design pattern of injection. Instead of the item itself, the container is responsible for injecting or linking objects with one another. There are three different classes involved.
  • Client class: Depending on the service class.
  • Service class: Providing service to the client class.
  • Injector class: Injects service class items into the client class.

7. How can you improve the website load time and performance?

If this is the full-stack developer interview question that you are asked, then the perfect answer to it will be;
There is a multitude of strategies to optimally optimize your website for performance, including:
  • Image optimization: Changing the file format can significantly reduce the size of an image's file. For instance, JPEG is perfect for images with plenty of colors and features, like photographs, while PNG format is best for transparent images with excellent clarity.
  • Keeping JavaScript and CSS externally: Keeping JavaScript and CSS in external files will prevent them from needing to be downloaded each time HTML content is loaded. The HTML content grows larger because the browser cache is not used in this situation. Because it is best practice and makes maintenance easier, you should always put CSS and JavaScript in external files.
  • Reduce redirects: A website's loading time will be affected by too many redirects. When a page redirects, HTTP requests, and answers are delayed. The time it takes for the site to load will be greatly reduced if you remove all unnecessary redirects.
  • Asynchronously load CSS and JavaScript files: Your website's CSS and JavaScript files can be loaded synchronously or asynchronously. Each file is loaded sequentially as part of synchronous loading, according to their sequence of appearance on your site. Asynchronous loading, as opposed to synchronous loading, enables many files to be loaded simultaneously, enhancing website performance.
  • Minify JavaScript, CSS, and HTML: By streamlining the loading of your files, your pages will load more rapidly. You can do the same to HTML, CSS, and JavaScript code. You can make your files smaller by getting rid of extra spaces, characters, and remarks. Your web pages will load more quickly as a result.

8. What's the difference between a Full Stack Engineer and a Full Stack Developer?

This full-stack developer interview question and the answer is the most basic one. Every stack developer should be able to answer it without taking time to think.
A Full-Stack engineer is a senior-level position holder with the same background as a Full-Stack developer but with project management expertise in system administration (the configuration and maintenance of computer networks and systems).

9. What is continuous integration?

The practice of automating and merging code changes into a single software project, frequently several times per day, is known as continuous integration, or CI. This DevOps technique aims to make it possible for developers to integrate their code changes into a single repository for automated testing and builds. Before integration, the new code is checked for correctness using automated tools. The core of the CI process is a source code version control system. Additional checks, such as automated tests for the quality of the code and tools for reviewing the syntax and style, are added to the version control system.

10. What are the advantages of continuous integration?

The key advantage of regular integration is that errors can be found more quickly and accurately. Finding the precise modification that produced an error is simply because the majority of introduced changes are small.
  • CI decreases MTTR (Mean Time to Resolution) due to the lower code modifications and simpler fault isolations.
  • You are less likely to have noncritical problems in your backlog when CI is implemented into your company's development process. These minor flaws are found and repaired before production before they are made available to the general public.

11. What is Callback Hell?

Callback Hell, often known as the Pyramid of Doom, is a typical anti-pattern in asynchronous programming code (code with numerous functions running simultaneously). It refers to the high number of nested "if" statements or functions. Simply said, Callback hell is a circumstance in which there are numerous asynchronous functions. Due to the interdependence of those methods, having so many callback functions stacked in so many layers could get very confusing. The employment of callback functions results in code that is challenging to comprehend and maintain and has a pyramidal appearance.

12. What are the latest trends or upgrades in Full Stack development, and how do you keep yourself updated?

Candidates that are enthusiastic about full-stack development should be aware of the following developments:
  • There has been high growth in real-time web apps, mobile web development, progressive apps, and libraries like ReactJs and VueJs.
  • Programming benefits from JavaScript improvements.
  • The appearance of an extension that is more compatible.
You can be asked by the interviewer how you stay updated with emerging developments in your field. You can describe how you acquire information and comprehension through online, classroom, or friend learning. That is a suitable response to the question. If you are asked this full stack developer interview question, show off any personal endeavors you have worked on that use your abilities now. You might also list the forums or webinars you frequently attend.

13. What do you mean by CORS?

CORS stands for Cross-Origin Resource Sharing. This mechanism allows web browsers to securely request resources (such as data or assets) from a different origin (domain) than the one that served the original web page.
By default, web browsers adhere to the same-origin policy, which means they restrict requests to resources from the same origin as the web page making the request. However, CORS provides a way to relax this policy and enable controlled access to resources from different origins.
Scripts running on a browser client can communicate with and access resources from other origins. In doing so, it expands and gives the SOP (Same-Origin Policy) more freedom. A website's ability to access resources outside of its source domain is limited by same-origin rules. For instance, the SOP will prevent a JavaScript application from calling an API (Application Programming Interface) hosted on a different domain. To get around limitations brought on the same-origin policies, a CORS policy is put into place.

14. What are the uses of Docker?

Dealing with the various environments across many machines and platforms is one of the trickiest issues in software development. To swiftly release software, you must be able to separate your apps from your infrastructure using Docker. Containers are executable components that contain all the operating system libraries. They contain dependencies required to run an application in any environment, and developers can use them to package and run their applications. No matter what software is installed on the host, containers are small and come equipped with everything needed to run programs.
  • As the code moves from the development computer to production, it must traverse various environments. Docker delivers a consistent environment from development to production, which speeds up code development and deployment.
  • The main goal of Docker is to make configuration simpler. You can run any platform with its configuration on top of your infrastructure using a virtual machine (VM). Docker provides the same functionality without the overhead of virtual machines.

15. What is an observer pattern?

The observer pattern is employed when there are one-to-many connections between multiple objects. All of an object's dependent objects are automatically updated and informed whenever one of them is modified. It fits within the domain of behavioral patterns. It explains how objects and the observer are coupled and offers assistance for broadcast-style communication. The term "observer" refers to an object that monitors the status of another item, whereas the term "subject" refers to the thing being monitored.
Remember that this full-stack developer interview questions and answers list is just a starting point. The depth of interview questions for full-stack developers may be different. It depends on the company to which you are applying and the specific job requirements. Therefore, it's always good to prepare and study the technologies and frameworks relevant to the role you're applying for.

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