Full-stack development job interview questions and answers

Are you planning to be a full stack developer?

With so many firms vying for the finest engineers, finding the right talent in the IT industry is difficult. And knowing who your fellow applicants are and asking proper questions during the interview are essential to stand out as good developers.

Let's get started on all you need to know about cracking interviews for full-stack development jobs. This blog guides you with full stack developer job interview questions and answers.

Who is a full-stack developer?

A full-stack developer is a programmer who creates software for both users and service providers. In simple language, a full-stack developer is familiar with the whole technological stack that makes up a website. They are fluent in both front-end and back-end programming languages, and primarily focus on web development. 

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The majority of full stack developers do not start out as full stack developers. Before pursuing full-stack, they generally work in a variety of roles. They also have a good understanding of business logic and user experience. In other words, they have sufficient business expertise to offer advice to others. 

Full stack developer skills

• Code Quality
• CSS
• JavaScript
• Node.js
• Problem Solving
• React
• REST API 
• Technical Communication

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Pros and cons of working in full-stack development

Full-stack developers are well-versed in the methodologies and products used in a business. This implies that, depending on their experience, individuals can always give important comments and ideas on a product or design. They can also assist other members of the team in ‘developing,' reducing the time and technical costs associated with team communication, and technology docking.

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Full Stack Developer Interview Questions and Answers for Freshers and Junior Professionals

1. What is your favorite programming language, and why is it your favorite?

Ans. A full-stack developer usually knows -

• HTML & CSS
• Python
• JavaScript
• MEAN

To answer why it’s your favourite, you must have some projects to back up your interest and support your work with examples. 

2. What is Pair-Programming? Have you ever done it?

Ans. Pair programming, which includes two developers working on the same terminal, is one of the basic aspects of extreme programming. While one developer is known as the "Driver" and is in charge of typing the codes, the other developer is known as the "navigator" and is in charge of evaluating codes.

3. What is CORS?

Ans. Cross-Origin Resource Sharing, or CORS, is a method of accessing online resources from multiple domains. Web scripts can be more freely connected with the external material of the originating domain with the help of  CORS. As a result, online services are more easily integrated.

4. Explain DevOps

Ans. DevOps is a new word in the IT world that refers to a technique that emphasizes the collaboration and communication of both software developers and other information technology (IT) professionals. It focuses on delivering software products more quickly and decreasing release failure rates.

5. What is Callback Hell?

Ans.The asynchronous function requires callbacks as a return parameter. A callback hell condition occurs when many asynchronous functions are chained together.

6. What is Multithreading?

Ans. Multi-threading is a technique for increasing the performance of a CPU. It is usually defined as a program’s capacity to be handled by several users at the same time. It is accomplished by the execution of a number of processes provided by the operating system.

7. What is Long Polling?

Ans. Long Polling is a web development strategy that improves data pushing from the server to the client. The client requests information from the server using the Long Polling pattern. Instead of delivering an empty resource, if the server does not have any information about the client, it holds the request and waits for some information to become available.

8. Explain the difference between REST and GraphQL

Ans. GraphQL does not deal with allocated resources, which is the most significant distinction between REST and GraphQL. Instead, everything is viewed as a graph, which is linked and can be searched to meet specific requirements.

9. What is the Event Loop?

Ans. Node.js is a single-threaded application but it supports concurrency via the concept of event and callbacks. As every API of Node js is asynchronous and a single thread, it uses async function calls to maintain the concurrency. Node uses an observer pattern. Node thread keeps an event loop and whenever any task gets completed, it fires the corresponding event which signals the event listener function to get executed.

10. Explain a use case for Docker

Ans. Docker is a lightweight virtualization platform that may be used on your local system or in the cloud. Despite the fact that they aren't technically separate devices, they provide many of the same advantages. Docker may encapsulate ancient programmes, making it possible to deploy them on servers that would be difficult to set up with older packages and software versions.

Full Stack Developer Interview Questions and Answers for Experienced Professionals

What is the difference between GET and POST?

Ans. 

GET:

GET is used for recovering the data. It carries the request parameter in the URL string, and it can be bookmarked.  

POST:

POST is mainly used for writing the data. It takes the request parameter in the message body, and it cannot be bookmarked.

1. Mention the success factors for continuous integration
2. Keeping a code repository up to date.
3. The construction process is automated.
4. Including a feature for self-testing in the build.
5. The construction is designed to be quick.
6. In a clone production environment, testing the build.
7. Providing team members with access to deliverables.
8. Providing team members with access to and visibility of the outcomes.
9. The deployment procedure is automated.

What is the difference between a blue/green deployment and a rolling deployment?

You have TWO full ecosystems in Blue/Green Deployment. The Blue environment is the one that is now active, whereas the Green environment is the one that you wish to upgrade to. The traffic is routed to your new green environment once you change the environment from blue to green. Until the green environment is established, you can delete or save your old blue environment as a backup.

There is just ONE full environment in Rolling Deployment. The code is deployed in a subset of the same environment's instances before being moved to another subset.

What are the disadvantages of GraphQL?

• You'll need to learn how to use GraphQL to get started. You must keep up with the ecosystem's fast evolution.
• You need to send the queries from the client, you can just send strings but if you want more comfort and caching you’ll use a client library -> extra code in your client
• You need to define the schema beforehand => extra work before you get results
• You need to have a GraphQL endpoint on your server => new libraries that you don’t know yet
• Graphql queries are more bytes than simply going to a REST endpoint
• The server needs to do more processing to parse the query and verify the parameters

5. What is the Temporal Dead Zone in ES6?

In ES6 let and const are hoisted (like var, class and function), but there is a period between entering scope and being declared where they cannot be accessed. This period is the temporal dead zone (TDZ).

Consider:

//console.log(aLet)  // would throw ReferenceError

let aLet;

console.log(aLet); // undefined

aLet = 10;

console.log(aLet); // 10

In this example, the TDZ ends when aLet is declared, rather than assigned.

6. What are the latest trends in full-stack web development?

The rise of Vue JS Functional, real-time web apps, progressive apps, and mobile web development.

Improvements in JavaScript help programmers.

Extensions that are more compatible are becoming increasingly common.

7. Explain Inversion of Control?

Ans. It's a wide word, but software developers use it to describe a design that allows layers and components in a system to be decoupled.

8.  What is Continuous Integration?

Continuous Integration is a method of testing, which involves the use of specifically developed and automated programmes. This procedure enables developers to quickly deploy codes during the production phase. This method is used by web developers to integrate scripts on a daily basis. These codes are automatically verified. Continuous Integration aids in the rapid detection and location of faults.

9. What are the advantages and disadvantages of using “use strict”?

Advantages

• It eliminates the possibility of accidentally creating global variables.
• Throws an exception for assignments that would otherwise fail quietly.
• Attempts to delete attributes that are not deletable (where before the attempt would simply have no effect).
• It is required that the name of the function argument to be unique.
• “This” is undefined in the global context.
• It catches some common coding bloopers, throwing exceptions.
• It stops the functioning of features that are confusing.

Disadvantages

• Many functionalities that most developers are accustomed to are missing.
• Function.caller and function.arguments are no longer accessible.
• It's possible that concatenating scripts written in various strict modes will cause problems.

10. When should you not use arrow functions in ES6? 

When we need to hoist a function — since arrow functions are nameless.

When we wish to utilise this/argument in a function, we have to rely on the outer context since arrow functions don't have this/argument of their own.

Arrow functions are anonymous when we want to utilise a named function.

General Full Stack Developer Interview Questions and Answers

Can you give an example of a suggestion you made that was implemented?

Ans. Your example of ideas that you’ve put into action should look something like this: I got the notion at my former job to devote a few hours on Fridays to assessing our efficiency. On Fridays, our workload was lower anyhow, so we were able to devote some time to enhancing our job.

What are the preferred methods of optimising a website's assets?

Ans. 

• Make fewer HTTP requests.
• Use a Content Delivery Network.
• Add an Expires header.
• Gzip components.
• Put CSS at the top.
• Move scripts to the bottom.
• Avoid CSS expressions.
• Make JavaScript and CSS external.

What is your checklist for doing code reviews?

Ans. 

1. Readability 

2. Maintainability

3. Security

4. Speed and Performance

5. Documentation

6. Reinventing the Wheel

7. Reliability

8. Scalability

9. Reusability

10. Patterns

11. Test Coverage and Test Quality

12. Fit for Purpose

4. Please walk me through the production issue you troubleshooted in the past 12 months.

Briefly explain what the mistake was, but don’t dwell on it.

Quickly switch over to what you learned or how you improved after troubleshooting that.

You might also explain the steps you took to make sure that the mistake never happened again.

5. What strategies do you follow for measuring the success of a new feature?

Step 1: Measuring the basic usage of the new feature

Step 2: Dig deeper into event properties to look for patterns

Step 3: Understanding what users are doing right before using the feature

Step 4: Building a behavioral cohort of people who used the feature to analyze how they compare to your overall user population

Step 5: Analyzing the impact of the new feature on retention

Step 6: Measuring the impact of the new feature on your key conversion funnels

Step 7: Measuring the impact of your new feature on engagement

6. Why did you choose the full-stack developer field as your career?

Ans. Full Stack Developers are multitasking experts with all-encompassing knowledge and skills. They are familiar with both client-side and server-side applications. They work on both the front-end and back-end of software development.

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Problem-Solving Full Stack Developer Interview Questions and Answers

When presented with a new project, how did you select the tools and technologies involved?

Ans. 

• Size and type of the project and complexity of the tasks.
• Development speed as well as cost and availability of IT experts.
• Presence of development tools and ready-made solutions.
• Project flexibility and scalability.
• Technical requirements, existence of detailed documentation.
• Support costs.

2. How do you protect against screen scraping?

Implementing JavaScript to set a cookie value that is checked by the web server can be a simple and effective technique. CAPTCHAS are also a good technique to prevent scraping; if an IP sends too many requests, CAPTCHAS can be presented to the end user to validate human interaction.

3. How do you debug a website?

In your Chrome browser, open the site you want to debug.

Right click over an element you want to debug. In this example, we're analyzing a yellow button.

Click "Inspect".

Which stack do you deal with being a full-stack developer ?

Depending on the project, what customers need may be a mobile stack, a web stack, or a native application stack.

What technologies and programming languages do you require from start to finish for developing a project?

It comes down to how effectively the interviewer can assess your readiness to begin working. This is a subject of debate. A full stack developer who is knowledgeable and proficient may easily be distinguished from the one who is inexperienced. As a result, you must reply with caution.

6. Describe some examples of a web application that you have built, and how did you do it?

The interviewer will get an understanding of how you think and how you deal with methods. The response you are giving should be straightforward and detailed, and why you would have developed it at the front or back end.

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Technical Communication in Full Stack Developer Interview Questions and Answers

What is your favorite programming language and why?

Ans. Full stack developers deal with a wide range of programming languages. Having only one favourite coding language might be a red flag. An applicant should ideally be fluent in a few languages, particularly the ones with which he can design the front end and others with which he can manage the back end. A candidate should be able to show this skillfully, remembering to include the most common ones like HTML, CSS, Python etc.

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Which technologies and languages would you need to develop a project from scratch?

Ans. This is a hypothetical question designed to help you understand how the recruiting manager will assess your preparedness to begin the job. It's a simple method to spot the difference between a good full stack developer and a novice. Those that have trouble communicating their views will have a tough time getting through at this point.

What is the best implementation or debugging that you have done in the past?

Ans. This is a difficult question to answer. This will offer the hiring manager a sense of the difficulty and style of previous projects you've worked on. You should be specific about the problems you encountered and the steps you took to address them. You might also discuss the lessons you learned from the situation.

How do you stay up-to-date with new industry trends?

Ans. Explain your engagement and understanding gained via continuous learning with friends, co-workers, or online - that is one correct approach to respond to this question. Also, if you have any personal projects where you employed your skills, now is a great opportunity to show them off. You might also include the webinars or forums that you attend on a regular basis.

5. What DBMS technologies are used for full-stack development?

Some of the DBMS technologies used for full-stack development are as follows

• MySQL
• Oracle
• SQL Server
• MongoDB 

6. Explain MEAN stack?

Ans. MEAN (MongoDB, Express, Angular, and Node) is a set of software development tools that is well-known for removing language boundaries. MongoDB, a NoSQL data storage text, is the foundation of a MEAN stack. The JavaScript frontend is built using the Express and Angular HTTP servers. The topmost tier of the Stack is Node, which is used for server-side programming.

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The above questions and answers are meant to help prepare you for the job interview for a full-stack developer role. In addition, no employer expects you to know everything, whether you are a newcomer or an experienced candidate. However, it is critical to be well-prepared for the interview and demonstrate enthusiasm for the position. Simultaneously, being truthful and upfront will always help in the long run.

FAQs

1. how do I prepare for a full stack interview?

Working your way through 'Cracking the Coding Interview' is a good approach to prepare. This book is a veritable gold mine of interviews. Make sure you know the foundations and fundamentals of computer science before going into a full-stack interview.

2. Why should we hire you as full stack developer?

The key benefit of hiring a full stack developer is that they can assist with the entire design structure and provide feedback at any level. Their services extend beyond web development to include system maintenance and optimization.

3. What skills should a full stack developer have?

HTML/CSS. While HTML stands for Hypertext Markup Language, CSS stands for Cascading Style Sheets. 

• JavaScript. 
• Git and GitHub. 
• Backend languages. 
• Web architecture. 
• HTTP and REST. 
• Database storage. 
• Basic design skills.

4. How much does it cost to hire a full stack web developer?

However, for a fresher, the true range can range from 3.5 LPA to 35 or even 40 LPA (according to Uber and Microsoft employment sources). For a decent start in your professional route in India, I'm very sure you may set a baseline of 7–8 LPA. If you're going to obtain anything less, aim to push yourself above the average line.

5. Which full stack is best?

• Spring Boot 
• Angular 
• Node JS + Express. 
• Django 
• Flask 
• Bootstrap