Full stack developer interview questions
A Full Stack developer is expected to have the functional knowledge and the ability to work on all aspects involved in building an application. A Full Stack developer should be able to write front-end code in Java, HTML, and JavaScript; create APIs and write backend code in Python/Java and Ruby; work on hardware and OS; have knowledge of networking and security; understand design and query databases.
An Overview of Full Stack Developer
Our vast collection of Full Stack Developer Interview Questions are the best resources for cracking your interviews.
Common Technologies a Full Stack Developer Should Have Expertise in:
- Front-end: HTML, HTML5, JavaScript, JQuery, CSS3
- Backend: Ruby on Rails, PHP, Angular2, Node.js
- Database: MySQL, MongoDB, CouchDB
- Debugging/Version Control: GIT, Grunt, Xdebug, Subversion
Whether you are looking for Full Stack Interview Questions, we have listed all possible Interview Questions related to full stack developer
1. Programming languages:
- Must be proficient in multiple languages, including PHP, Java, C #, Ruby, Perl, Python, etc.
- Must be familiar with different ways to structure, design, implement, and test the project based on languages.
2. Frameworks:
Must know the words that are accompanied by development frameworks, such as Spring, JAVA, MyBatis, Python Django, PHP think PHP, Hibernate, nodeJs express, yin, etc.
3. Front-end:
Must master necessary front-end technologies such as CSS3, HTML5, and JavaScript. Additional study of third-party libraries such as JQuery, SASS, LESS, AngularJS, or REACT is also required. These Mean Stack Interview Questions will help you prepare for your interview
4. Databases:
Knowledge of at least one database is expected. Currently, the popular databases are MySQL, Oracle, MongoDB, SQLServer and Redis.
5. Design ability:
Basic knowledge of the principle of prototype design, UI and UX design is needed.
Most Frequently Asked Full stack developer interview questions And Answers With Examples:
- What should full stack developer know?
- What is the difference between GET and POST?
- What is RESTful API and why it is used?
- What do you mean by data attributes and why it is used?
- Explain the difference between defer and async?
- What are the difference between "resetting" and "normalizing" CSS? Explain
- What does acid stand for in database?
- Explain the difference between the left join & right to join?
- What are normalization and denormalization?
- What are two phases commit in the database? Explain
- Explain the difference between horizontal scaling and vertical scaling in the database?
- Explain the difference between MVP and MVC? Explain
- What the differences are between == and ===?
- What is event bubbling and capturing in javascript?
- What do you mean by promise?
- What is the prototype in javascript and how do you use it?
- What do you mean by Closures?
- Explain the differences between abstract classes and interfaces?
- What do you mean by final class and final method?
- What is the difference between constructor & destructor?
- What is Express.js?
- What is Node.js and why it is used?
- Explain the difference between AngularJS and Node.js?
- What is the difference between Nodejs, AJAX, And JQuery?
- What do you mean by callback in Node.js?
- What is MEAN Stack?
- What do you mean by routing in angular js?
- Explain the difference between directive and component in angular. Js?
- What do you mean by design patterns?
- What is multithreading?
- What do you mean by CORS and how does it work?
- How can the web application load time be reduced?
A full stack developer should know:-
- Programming languages:
Must be proficient in multiple languages, including PHP, Java, C #,
Ruby, Perl, Python, etc. Must be familiar with different ways to
structure,design, implement and test the project based on languages.
- Frameworks:
Must know the words that are accompanied by development
frameworks, such as Spring, JAVA, MyBatis, Python Django,
PHP think PHP, Hibernate, nodeJs express, yin, etc.
- Front-end:
Must master necessary front-end technologies such as CSS3
HTML5, and JavaScript. Additional study of third-party libraries
such as JQuery, SASS, LESS, AngularJS, or REACT is also required.
- Databases:
Knowledge of at least one database is expected. Currently, the popular
databases are MySQL, Oracle, MongoDB, SQLServer and Redis.
- Design ability:
Basic knowledge of the principle of prototype design, UI and UX design is needed.
| S.no | GET | POST |
|---|---|---|
| 1. | GET is used for recovering the data | POST is mainly used for writing the data |
| 2. | It carries the request parameter in the URL string | It takes the request parameter in the message body. |
| 3. | It can be bookmarked | It cannot be bookmarked |
A RESTful API is also known as RESTful web service. Full form of REST is Representational state transfer, and complete kind of API is Application program interface. This program interface uses HTTP protocol to define the set of function such as GET, PUT, POST and DELETE data. RESTful API is used.
REST is mostly used in developing Web applications.
HTML 5 has “data-*” which are custom attributes defined by the developer. They are used when any existing characteristic is not suitable to be used. These attributes are only used on the page they are written on, and they do not need AJAX calls.
These are Global attributes, so they can be applied to any element.
Point to be noted: Go through this Q&A very thoroughly as this is one of the essential full stack interview questions.
| S.no | defer | async |
|---|---|---|
| 1. | It downloads the file during the HTML parsing but executes the data after the parsing is completed. | It downloads the data during the HTML parsing, but it stops the parsing from executing the downloaded file. |
| 2. | Defer is used when the script relies upon another script. | Async is used if the script does not rely upon any scripts. |
| S.no | resetting | normalizing |
|---|---|---|
| 1. | Resetting removes all the built-in browser styling. | Normalizing makes the integrated browser styling consistent across the browsers. |
| 2. | It does not provide bug fixes. | It includes bug fixes. |
The acronym ACID stands for Atomicity, Consistency, Isolation, and Durability.
| S.no | LEFT JOIN | RIGHT JOIN |
|---|---|---|
| 1. | It gets the records from the rows of the LEFT side linked table and only the matching records from the RIGHT table. | It gets the records from the rows of the RIGHT side linked table and only the matching records from the LEFT table. |
This is a very critical question in mean stack interview questions and answers.
Normalization means merely a process of reducing or eliminating the data redundancy. As a result, space is saved, and the consistency of data is increased.
The denormalization is an optimization process to increase the data redundancy in the database. As a result, the joins are avoided, and the performance of the database structure is improved. Denormalization is done after the normalization process
Two-phase Commit (2PC) is the feature of transaction processing systems which enables databases that they return to the pre-transaction state if an error condition occurs. The two-phase commit strategy is designed to make sure that either all the databases are updated or none of them is updated. As a result, the databases remain synchronized.
| S.no | Horizontal scaling | Vertical scaling |
|---|---|---|
| 1. | More machines are added into your existing resources | More power i.e. CPU, RAM is attached to the current machine |
| 2. | Horizontal scaling there is no limit | Vertical scaling depends on the capacity of the machine |
| 3. | Licensing fees is more | Licensing fees is less |
| S.no | MVP | MVC |
|---|---|---|
| 1. | View handles the user gestures | The controller manages the user gestures |
| 2. | The interaction with the model is passed through the presenter | The view can query the model directly |
| 3. | Provides full sport to unit testing | Provides limited support to unit testing |
| S.no | == | === |
|---|---|---|
| 1. | If the variables are not of same types, then it converts one variable type to another and performs the operation | If the variables are not of the same type, then it will not achieve the process and will return false |
Event Bubbling and Event Capturing are the ways of the event propagation in the HTML API when an event occurs in an element which is located inside the other part and both the parts have registered a handle with the recently happened event. Here the event propagation mode identifies that in which order the elements receive the event.
In the case of Event Bubbling, the event is first captured and also handled by the innermost element, and then the event is propagated to the outermost element.
In the case of Event Capturing, the event is first captured and also handled by the outermost element, and then the event is propagated to the innermost element.
A Promise is an object which shows the result of the asynchronous operation. The result can be a resolved value or a reason why the process failed like “a network error occurred.
A promise can be any of the 3 states:-
- Pending - the promise’s result hasn’t yet been identified because the asynchronous operation has not been completed yet.
- Fulfilled - the asynchronous operation has completed, and the promise has now a resolved value.
- Rejected - the asynchronous operation has failed, and the promise has a reason that indicates why the process failed.
Prototype are objects created in Javascript. They are the “parent” objects. If we want to create common tasks (properties/methods) for all the objects inherited from the parent object we need to define them in the prototype object.
This is one of the essential questions in full stack developer interview questions.
A closure is the capability of an inner function to have access to variables in local scope in which internal function was created. Even if the out function has finished execution, closure means the inner function has access to its local variables.
| S.no | Abstract Class | Interfaces |
|---|---|---|
| 1. | Abstract classes cannot be implemented. | The Interfaces needs to be implemented. |
| 2. | They are models which can have some methods to be used by all the inherited children. | It is a contract, where the receiver is asking a specific type of input and sender agrees to send it that way. |
| 3. | Abstract classes can have private methods. | Interfaces can not have private methods. All the plans are public. |
Final classes cannot be subclassed; it is not open for change and can be used reliably for common execution of routines. “String” class in Java is an example of a final class. This is done for security and sometimes for efficiency.
Final methods cannot be overridden. They are not open to change. This prevents accidental changes which may result in crashing of application.
| S.no | Constructor | Destructor |
|---|---|---|
| 1. | It allocates the memory to an object. | It deallocates the memory of an object. |
| 2. | It accepts argument. | It does not take an argument. |
| 3. | In a class, there can be multiple constructors. | In a class, there can only be one destructor. |
Express.js is a web application server framework. It is used for Node.js. It helps to create node.js applications in less time. It also provides security-related help for node.js.
Node.js is a server environment to be used for web development. Node.js is an open-source server. This is based on google chrome’s JavaScript engine V8.
Node.js is used to create applications in less time and useful for data-intensive applications.
| S.no | AngularJS | Node.js |
|---|---|---|
| 1. | Written only in Javascript. | Written in Javascript, C, C++. |
| 2. | It is a client-side web application | It is a server-side web application |
| 3. | It is a web application framework in itself | It is not a framework but has a framework like express.js |
| S.no | Node.js | AJAX | JQuery |
|---|---|---|---|
| 1. | It allows JavaScript to be run without a browser | It a way for JavaScript to request the data from a server but without refreshing the page or blocking the application. | It is a JavaScript library which was built to automate and simplify the common web tasks like AJAX |
Kindly go through this question before going for the full stack interview questions.
A Callback Function is a function which is passed as a parameter to another function,.The callback function run inside of the function into which it was passed. JavaScript Callback Functions can be used synchronously, and it can also be used asynchronously. Application programming interfaces of the Node are written in such a way that they all support callbacks.
MEAN stack is a user-friendly free and open-source JavaScript software which is used for building the dynamic web sites and the web applications. The advantage of using the MEAN stack is that only language JavaScript runs on all the levels of the applications which makes it efficient.
MEAN stack is the composition of:-
- MongoDB as the database
- Express.js as the web framework which runs on Node.js
- AngularJS as the frontend framework
- Node.js as the server platform.
If the developer wants to go through different pages in a single page application and also with no reloading of the page then the ngRoute module is used. It routes the application to different pages with reloading of the complete application.
| S.no | Directive | Component |
|---|---|---|
| 1. | It is behavior that has been added to the existing components. | Components have its own view i.e., HTML and styles. |
| 2. | There can be multiple directives in one element. | There can be only one component in one element. |
The interviewer will definitely ask this question in the full stack developer interview questions .
Multithreading is the ability of the Operating system or the program to handle the multiple user requests at a time for its resources. Here a user can be a human or another program.
CORS stands for Cross-Origin Resource Sharing. It is a standard to share the selected resources between the web applications running on two different domains.
The ways to minimize the load time of a web application are:-
- Minimize the resources requested by a page
- Implement Lazy load so that the part of the page only loads when the access that part.
- Use Distributed networks for common resource files.