In the field of web creation, a full stack developer is a unicorn. A full stack web developer must be knowledgeable about front-end development, database administration, and back-end growth. A Full Stack developer should be capable of writing front-end programming in Java, HTML, and JavaScript; developing APIs and writing backend code in Java and Ruby; dealing with hardware and operating systems; understanding networking and security, and designing and querying databases. If you're eager to ace the next full stack interview questions and answers round, here's a set of 40 questions that will help you.
Full Stack Developer Interview Questions and Answers
A Full Stack developer is considered to possess technical expertise and the capacity to operate in all areas of application development. The full stack interview questions that will be asked from you will not only depend on the theoretical knowledge you possess but also its practical application, the basics, and some advanced skills.
1. What is DevOps?
DevOps is a relatively recent concept in the information technology (IT) world, and it refers to a methodology that stresses teamwork and coordination between computer programmers and other information technology (IT) practitioners. It is focused on developing tech products more quickly and reducing release failure rates.
2. Which programming languages should a full stack developer be familiar with?
A full stack developer should be familiar with the following:
1. Computer languages
Must be fluent in a variety of languages, including PHP, Java, C#, Ruby, Perl, and Python, among others. Must be acquainted with various language-specific approaches to structuring, designing, implementing, and testing projects.
2. Frameworks
Must be familiar with the terms associated with development frameworks, like Spring, Java, MyBatis, Python Django, PHP, Hibernate, nodeJs express, and yin.
3. Front-end design
Must be proficient in necessary front-end technology, including CSS3, HTML5, and JavaScript. It is also essential to learn third-party libraries like JQuery, SASS, LESS, AngularJS, or REACT.
4. Access to databases
At a minimum, familiarity with at least one database is needed. MySQL, Oracle, MongoDB, SQLServer, and Redis are the most common databases.
5. Capability for design:
Working knowledge of the principles of prototype design, user interface design, and user experience design is needed.
Note: As a full stack developer this is one of the most basic and important full stack interview questions.
3. What is Pair-Programming?
Pair Programming is a basic feature of intense programming in which two developers function together on that terminal. The developer who writes the code is referred to as the "driver," while the Developer who checks the code is referred to as the "navigator."
4. Describe a case in which Docker will be useful.
Docker is a low-cost method of running virtual machines on a local computer or in the cloud. While they are not purely distinct computers and do not need an operating system to boot, they have all of those advantages.
● Docker will encapsulate legacy programs, enabling them to be deployed on servers that would be difficult to configure with older packages and product iterations.
● Docker may be used to build test boxes as part of the deployment phase, allowing for continuous integration testing.
● Docker could be utilized to configure virtual machines in the cloud, while swarm can be used to orchestrate clusters.
5. What is a RESTful API and how does it work?
RESTful APIs are often referred to as RESTful network services. REST stands for Representational state transfer, while API stands for application program interface. This software interface defines a series of functions such as GET, PUT, POST, and DELETE data using the HTTP protocol. It makes use of a RESTful API. REST is mostly used in web application creation.
You may also read: Top Popular JAVA Interview Questions
6. What is the Bridge Pattern's purpose?
The Bridge Pattern is used where an abstraction must be decoupled from its implementation in order for the two to stand alone. This trend is advantageous where the class, as well as its associated roles, differ. If the class is an abstraction, the function is the implementation. This pattern makes use of an interface as a buffer, separating the characteristics of concrete classes from the functionality of interface implementer classes. As a result, all groups may be manipulated/modified independently of one another.
7. What is the distinction between git fetch and git pull?
Git pull performs a git fetch accompanied by a git merge. When you are using pull, git attempts to automate the job. Since git is context-sensitive, all pulled commits would be merged into the branch on which you are actually operating. Pull merges the commits immediately without requiring you to check them first. If you do not treat the divisions carefully, you can encounter regular disputes.
When you fetch, git collects any commits from the goal branch that are missing from your current branch then stores them in the local repository. It does not, though, integrate them into the new division. This is especially helpful if one needs to maintain the repository current but are operating on anything that can fail as a result of the upgrade. Merge is used to incorporate the commits into the master branch.
Note: This is one of the most important full stack interview questions.
8. What are the words "event bubbling" and "capturing"?
Event Bubbling and Event Capturing are two methods for the HTML API to propagate events where an event happens in an object that is included within another element and all sections have recorded a handle to the recently occurred event. The event propagation mode specifies the order in which the events are received by the elements.
In the instance of Event Bubbling, the innermost component captures and handles the event first, and then propagates it to the outermost component. In the instance of Event Capturing, the outermost component captures and handles the event first, and then propagates it to the innermost component.
9. What is the fundamental distinction between REST and GraphQL?
The primary distinction between REST & GraphQL is that in the REST paradigm, the type/shape of a resource as well as the method for extracting it are inextricably linked, while in GraphQL, these two terms are entirely separate. The fundamental distinction between the two is that, unlike REST, the definition of a resource is not tied to the method of retrieval in GraphQL.
10. Generally, incorporating third-party providers into API queries results in longer response times. How can this be avoided? Are you aware of any developments that could be useful in resolving this issue?
The most effective method of resolving this problem is by the usage of queues. As a result, once an API request is generated, a new job is produced and queued. This job will be performed in a separate thread from the requested endpoint, enabling the server to react immediately.
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Next in this post of full stack interview questions are some of the most commonly asked questions from developers.
Most Common Full Stack Developer Interview Questions
The most frequently asked full stack interview questions give you a better picture of what to expect in the interview. So, let us start by looking at the most common full stack interview questions.
1. What is the distinction between an MVP and an MVC architecture?
MVP is a subset of an MVC (Model View Controller) pattern. It is used to build graphical user interfaces. Commonly, the MVP pattern enables the separation between presentation and reasoning layers.
The following is the distinction between the two:
MVP:
● The view is in control of interface movements.
● The presenter is the conduit for contact with the model.
● Provides comprehensive support for unit testing
MVC:
● The controller is in charge of the user's gesticulations.
● The view will explicitly query the model.
● Supports unit testing in a small way
Note: This is one of the most important full stack interview questions.
2. What do you imply when you say "promise"?
A Promise is a type of object that indicates the outcome of an asynchronous process. The outcome could be a resolved attribute or a justification for the failure of the operation, such as "a network error occurred."
A promise will take one of three forms:
● Pending - The outcome of the promise has not yet been determined since the async operation has not yet ended.
● The async operation has finished, and the pledge now has a settled value.
● Rejected - The async procedure crashed, and the pledge includes a reason for the failure.
3. How can you keep any bot from scraping an open API?
Given that perhaps the data in the API is freely available, it is practically impossible to fully avoid data scraping. There is, though, one approach that may stop bots and humans alike. This is referred to as Rate Limiting or Throttling.
Throttling enables a system to make a limited number of requests during a defined time period, during which it will display the following HTTP error:
“429 Excessive Attempts”
While this is an efficient way of preventing bots from scraping a publicly available API, you must trace the system in question using more than just the IP address, since the IP address is not exclusive to the device and therefore can result in the loss of access to the API over an entire network.
4. What exactly is a MEAN Stack?
The MEAN stack is a series of JavaScript-based technology for web application design and development. MongoDB, ExpressJS, AngularJS, and Node.js are the four main technologies that comprise MEAN.
It is a full stack programming toolkit that enables the creation of a quick and dependable web application. It's an easy-to-use stack that's perfect for developing interactive websites and apps. This open and free stack enables the accelerated development of web application prototypes in an orderly and systematic manner.
5. What is the difference between a final class and a final method?
Final classes are not subclassable; they are immutable and are used efficiently to execute common routines. The Java "String" class is an illustration of a final class. This is achieved for safety and, on occasion, performance. The final methods are not overridable. They are not adaptable. This avoids unintended modifications that may result in the program crashing.
You may also read: Frequently Asked SQL Interview Questions
6. What characteristics do you believe a Full Stack Developer should possess?
This is a fairly clear topic in and of itself, but it is particularly critical for newcomers. Be certain to add the following while listing the skills:
● The technology used in the front-end
● Languages of development
● Cache and database
● Fundamental design abilities
● Areas of expertise in a server
● The capability of interacting with APIs
● The capability of utilizing a version control system (VCS)
If a question like this pops up in your full stack interview questions, be confident to add more skills as you like.
7. What are the responsibilities of Full Stack Web Developers?
A Full Stack Web Developer is anyone who is comfortable with both client and server app development. Along with CSS and HTML, they understand how to program a browser, a database, and a server.
To properly grasp the function of a Full Stack developer, it is essential to understand the components of web creation - front end and back end. The front end of an application is the observable portion in which the customer communicates, while the backend contains business logic.
You must be wondering why is this question even on the list of full stack interview questions? Because most candidates know what the role is but are unable to answer it properly.
8. What exactly is the Observer pattern?
The observer pattern (alternatively called the Publish-Subscribe pattern) has been used where there is a one-to-many connection between objects, for example, when one object is changed, its dependent objects should be immediately informed. The observer pattern is a type of behavioral pattern.
The subject as well as publisher is an element that has a one-to-many connection with other entities that are involved in its state. Observers are alerted if the subject's condition shifts and may respond appropriately. The subject must notify an unlimited number of dependent observers, and any number of observers may subscribe to the subject in order to obtain these updates.
The observer pattern makes use of two distinct actor classes:
● The abstract class Observer (os Subscriber) contains an update() method that will be invoked by the subject to inform it of a shift in the subject's state.
● Additionally, the Subject (or Publisher) class is an abstract class, defining four key methods: attach(), detach(), setState(), and notify()
9. Object-Oriented Programming: What is it?
Object-oriented programming (OOP) is a programming model that is built on the idea of "objects". These objects may contain data in the form of fields, which are frequently referred to as attributes, and code in the form of procedures, which are frequently referred to as methods. A characteristic of objects is that their corresponding procedures will reach and often change the object's data fields (objects have a concept of "this" or "self").
OOP is a programming language that allows for the development of computer programs by the use of elements that communicate with one another. While OOP languages come in a wide variety of flavors, the most common ones are class-based, which means that elements are instances of the class, which usually often define their category.
OOP is a very powerful concept for full stack developers. Don’t forget to check out some OOP full stack interview questions before your interview.
10. What is Inversion of Control (IoC) and how does it work?
Inversion of Control (IoC) is a general concept used by software developers to describe a pattern for decoupling device components and layers. Object-oriented programming is where it's most often seen. With the aid of Inversion of Control, control of objects or parts of a program is passed to a system or container. Various methods, such as the operation locator template, plan architecture pattern, warehouse pattern, and dependency injection, may be used to do this.
You may also read: Top Python Interview Questions
11. What is Continuous Integration, and how does it work?
Continuous Integration refers to the use of built-and-automated code for testing and development. This makes it simple for programmers to deploy code during the development phase. During the development period, developers would integrate a code every day. Any code is immediately reviewed. The codes are then deployed to development without the need for human interference. This can diagnose issues easily and at various levels of development.
12. What are the benefits and drawbacks to utilizing "use strict"?
The expression ‘use strict' is used to switch on the strict mode for whole scripts or specific functions. The strict mode allows you to use a more limited version of JavaScript.
Advantages include:
● It makes it difficult to establish global variables by mistake.
● Does assignments that would normally throw an error and passively crash.
● Attempts to uninstall assets that are not deletable are thrown.
● The names of feature parameters must be special.
● In a global setting, this is undefinable.
● It throws exceptions when it detects any typical coding errors.
● It switches off functions that are unclear or badly designed.
Contrary to popular belief, there are a number of disadvantages of using this method.
● Many functionalities that certain developers are accustomed to are absent.
● Function.caller and function.arguments are no longer available.
● Concatenation of scripts written in various strict modes can result in problems.
13. What exactly is polling?
Polling is a technique in which a recipient requests fresh data from the server on a regular basis. There are two types of polling: long polling and short polling.
Long polling is a production pattern that sends data from the server to the client as quickly as possible. Short polling calls are made at predetermined intervals and are AJAX-based.
14. What is the best way to create a stable Continuous Integration process?
First and foremost, we must keep an eye on the project's code. The construct could then be automated and self-testing. Every day, everybody can combine codes. The construct must be simple and up to date in order to meet the production's needs. Last but not least, the implementation procedure can be automated. Continuous Integration can be effective in detecting issues and speeding up output with these measures.
15. Explain AMD vs CommonJS?
Both are methods for implementing a module structure, which was not native to JavaScript until ES2015. AMD is clearly asynchronous, whereas CommonJS is synchronous. AMD, with its help for asynchronous module loading, is more geared toward browsers, while CommonJS is built for server-side growth.
AMD syntax can be very verbose, and CommonJS is more akin to how import statements are written in other languages. Most of the time, AMD is redundant since you wouldn't profit from the async loaded properties if you served all of your JavaScript in a single concatenated package format. Additionally, the CommonJS syntax is more similar to the Node style of writing modules, and there is fewer context-switching overhead while switching among client and server JavaScript creation.
16. What is the difference between blue-green deployment and rolling deployment?
A new version of the program steadily removes the existing one in a rolling deployment. During the upgrade phase, all existing and current versions of the code can coexist without compromising the user interface or features.
Two similar development environments run in tandem in a blue-green deployment. One is a blue environment that receives all user traffic and runs the output environment. Another thing you want to improve is the green world. Both apps and the network runtime are configured in the same way. When the atmosphere is changed from blue to green, traffic is led to the green environment.
17. What is Long Polling, and how does it work?
Long Polling is a software development pattern for getting data from the server to the user without having to force it. The client demands details from the server utilizing the Long Polling pattern. Instead of transmitting an empty resource, if the server does not possess some details about the client, it keeps the request and waits for any information to become accessible.
18. Are there any drawbacks to using GraphQL?
Contrary to popular belief, there are a number of disadvantages of using this method.
● You'll need to learn how to use GraphQL to get started. You must keep up with the ecosystem's accelerated evolution.
● You must submit the queries from the database; you can simply send strings, but if you want more convenience and caching, you can need a client library -> additional code in your script.
● You must first describe the schema, which means further analysis until you can see the performance.
● You'll need a graphql endpoint on your computer, which may need you to learn new libraries.
● Graphql queries take up more space than visiting a REST endpoint.
● To parse the query and validate the criteria, the server must do additional computation.
Note: For full stack interview questions you should prepare the advantages and disadvantages of using query languages like GraphQL.
19. In JavaScript, how can you explain prototype inheritance?
In a language that implements classical inheritance, such as Java, C#, or C++, you construct a class—a template for your properties—and then you can either construct new objects from that class or expand it by specifying a new class that augments the original class.
In JavaScript, you construct an element first (there is no definition of a class), then augment it or create new structures from it.
In Javascript, every element has a prototype. The inheritance structure in JavaScript is prototypical rather than class-based. When a message enters an entity, JavaScript will first try to locate a property in that object; if it cannot, the message will be forwarded to the object's prototype, and so on. This is known as prototype inheritance or prototype chain.
Constructor functions are the most common way to build template chains in JavaScript. The ‘this’ keyword in JavaScript injects an implied connection to the current object being generated while we use new. This relation is often indirectly returned at the end of the feature.
Note: This is one of the most important full stack interview questions.
20. What is the difference between normalisation and denormalisation?
The term "normalisation" simply refers to the method of minimizing or removing data duplication. As a consequence, storage capacity is saved, and data quality is improved.
Denormalisation is a storage optimization mechanism that increases system redundancy. As a consequence, joins are avoided, and the database structure's efficiency is enhanced. The normalisation mechanism is followed by denormalisation.
21. What is Continuous Integration, and how does it work?
Continuous Integration is a method of research that involves the use of specifically built and programmed codes. This procedure enables developers to quickly execute code throughout the development phase. This method is used by web developers to combine codes on a daily basis. These codes are immediately verified. Continuous Integration aids in the rapid detection and location of mistakes.
22. What is the meaning of multi-threading?
Multi-threading is a technique for CPU efficiency. In general, it refers to a program's capacity to be handled by several users at the same time or to handle several requests by the same person. Multi-threading is achieved by running several tasks at the same time, as long as the operating system allows it.
Note: This is one of the most important full stack interview questions.
23. What stages are included in Continuous Integration?
One phase at a time is how continuous integration operates.
● Keep track of the code that would be included in a project.
● The build must be automated and self-testing.
● Every day on the build, everybody can incorporate code.
● The build should be revised in accordance with the development specifications.
● Get the implementation phase more automated.
24. What is the CSS Box model?
The CSS Box model is used to determine how design is shown on a web page. A rectangular box represents each feature that will be shown on the web page. For the material to be viewed on the frame, margin, lip, lining, and content borders are used with specific scale and colour, among other things.
25. What are the various kinds of design patterns?
The following are the various types:
● Creator, singleton pattern, concept, abstract factory, singleton design, and other creational patterns are used to construct objects.
● Structural patterns allow for an easier architecture by adding a basic method for realizing relationships between different individuals such as converter, facade, bridge, decorator, proxy pattern, and so on.
● Behavioural patterns: They are used to determine how objects communicate with one another.
26. What is the three-tier model?
For any program, a three-tier architecture consists of three levels. The presentation layer, which is linked to the front end and deals with user experience, and the enterprise layer, which is linked to the back end and deals with data validation. The database layer is the third layer, and it is responsible for data collection.
27. What is the method of debugging a complex program?
It is best to evaluate the issue before debugging. It's important to double-check the inputs and outputs. The test data is tested for possible inputs and outputs in the input and output data sets. Rectification entails making the same mistake in the next step or mission.
28. What is Dependency Injection, and how does it work?
IoC is implemented using the Dependency Injection architecture pattern. Rather than the entity itself injecting particles or binding objects with other objects, the container does so. There are three different categories of groups involved.
● The provider class determines the client class.
● The recipient level is served by the service class.
● Injector class: This class injects objects from the provider class into the client class.
29. What exactly is the observer pattern?
The observer pattern is used to describe a one-to-many dependence between objects, in which when one entity changes its state, all of its dependents are immediately informed and modified. The viewer is the entity that observes the condition of another entity, and the subject is the one that is being observed.
30. What exactly do you imply when you say "data attributes"?
Data Attributes are being used to preserve custom data that is only accessible via the client or website. They allow us all to store additional information on the basic, semantic HTML components. The accumulated data will be included in the JavaScript tab to make the user interface more interactive.
There are two parts of a data attribute:
● There must be at least one character following the prefix "information-" and no uppercase characters.
● A string value may be used as an attribute.
Conclusion
Full stack development necessitates a deep experience in computer engineering, web development, and database administration since it requires dealing on both the back and front ends of an application. If you're preparing for an interview for a full stack developer role, the full stack interview questions above will help you ace it.
You may also read: Best Answers to Why Should We Hire You?
Author Bio:
Nupur Trivedi, Technical Lead, SCIKEY
Nupur is Technical Lead at SCIKEY with 4 years of experience in web and hybrid mobile apps. She enjoys finding new ways to improve UX and loves to work on different technologies. Besides that, she is a photography hobbyist, occasional blogger, and nature lover.
