Most Asked Full Stack Developer Interview Questions

Things are often not as tight for a fresher as they are for a mid-level or senior professional. The questions usually begin with an icebreaker. As there aren't many projects that such a professional can display, the hiring manager does his best to analyse as much as he can during an interview.

1.What information should a full-stack developer have?

ANS:The following is what a full-stack developer must introduce: Programming Languages: A full-stack developer must be able to code in many languages such as Java, Python, Ruby, C++, and others. Based on the programming language, one must be familiar with various techniques to plan, develop, implement, and test the project. Front End: Knowledge of front-end technologies such as HTML5, CSS3, Angular, and others is required. Understanding third-party libraries like as jQuery, Ajax, and SASS provides additional benefits. Frameworks: Spring, Spring Boot, MyBatis, Django, PHP, Hibernate, JavaScript, yang, and other development frameworks are examples of proficiency in words. Databases: At least one database should be acquainted. It is adequate if you are familiar with MySQL, Oracle, and MongoDB. Design Ability: Prototype design skills, such as UI and UX design, are also required.

2.What is pair programming, and how does it work?

ANS:Pair programming (a fundamental component of programming) is a strategy for agile software development in which two developers collaborate on the same computer (system). The driver is the developer who produces the code, whereas the navigator is the developer who evaluates (code checks, proofreads, and spell checks) it. The programming approach is more efficient, and there are less coding errors. Pair programming has the drawback of increasing the cost.

3.What is the difference between MVC and MVP?

ANS:Both MVC and MVP are architectural paradigms for developing apps. MVC - Model View Controller is the abbreviation for Model View Controller. It's an architectural paradigm for creating Java Enterprise Applications. It divides a programme into three logical parts: Model, View, and Controller. It isolates the display layer (View component) from the business-specific logic (Model component). MVP - Model View Presenter is an acronym for Model View Presenter. The MVC architectural pattern inspired it. It adds an extra layer to the architectural pattern (known as indirection) that divides the View and Controller into View and Presenter. A Presenter takes the position of the Controller. In MVC, it's on the same level as View. It includes the View's UI business logic. The Presenter receives the invocations straight from the View. It keeps the action (events) going between the View and the Model. The View is not directly communicated with by the Presenter. It connects with the user via a user interface.

4.How can the scalability and efficiency of a website be improved?

ANS:To improve a website's scalability and efficiency, we may utilise the following methods: DNS lookups are being reduced. Keeping URL redirects to a minimum Avoiding the use of redundant codes Avoiding images that aren't essential Making use of browser caching JavaScript parsing is deferred to avoid inline JavaScript and CSS. For responsive images, use srcset. All assets should be hosted on a cookie-free domain, preferably via a CDN.

5.In functional programming, what is referential transparency?

ANS:Referential transparency is a characteristic of a programme in which any two expressions in the programme with the same value may be replaced for one another anywhere in the programme without altering the program's outcome. It's a programming language that's utilised in functional programming.

6.What is a RESTful API, and how does it work?

ANS:Representational State Transfer is the abbreviation for Representational State Transfer. It's an architectural approach for developing Web Services. To access and utilise the data, it makes HTTP queries. We have the ability to create, edit, read, and remove information. The code that allows two software applications to connect with one other is known as an API (Application Program Interface) for a website. It enables us to develop code that requests services from an operating system or another programme.

7.What exactly do you mean by promise, and how do you define its states?

ANS:An asynchronous function can return a promise, which is an object that can be returned synchronously. It might be in one of three states: A promise will be in the fulfilled state if it has invoked the onFulfilled() function. Rejected: A promise will be in the rejected state if it calls the onRejced() function. Pending: A promise is in the pending condition if it has not yet been fulfilled or rejected. If and only if a promise is not pending, it will be fulfilled.

8.How can a web application's load time be reduced?

ANS:The following methods can be used to improve a web application's load time: Image size and format should be optimised. Content should be compressed and optimised Redirects should be avoided. The web page should be cached. Reduce the number of HTTP requests Dependencies should be optimised Place the CSS reference at the top of the page. Place the script reference at the bottom of the page. Externalize JavaScript and CSS.

9.What exactly is continuous integration and delivery (CI/CD)?

ANS:CI/CD is a best practise for developing apps with frequent and quick code changes. It is sometimes referred to as the CICD pipeline. It is a DevOps and agile approach that is extensively utilised. Continuous integration is a coding philosophy or deployment technique in which developers integrate their code multiple times per day in a common repository. Because contemporary applications necessitate the development of code across several platforms. Continuous integration aims to provide an automated process for building, testing, and packaging an application. Where CI ends, continuous delivery begins. It distributes the application to the infrastructure of your choice automatically. If any modifications are made to the code, CD guarantees that it is sent automatically.

10.Which architectural styles are most commonly utilised in application design?

ANS:The following architectural design patterns are used in software development: Controller for Models and Views The Master-Slave Relationship Pattern with Layers Presenter of Model Views Monolithic Structures Pattern of Event-Driven Architecture

11.What is the definition of lengthy polling?

ANS:Without employing the WebSocket or Server-Side Events protocols, long polling is an effective way to establish a steady server connection. It is built on top of the traditional client-server paradigm. It's worth noting that Node.js use the same methodology as the following development model. The client submits the request, and the server answers until the connection is opened since it contains new and unique information. A request to the client can be sent as soon as the server answers. The server will return a query once the data is accessible. It kicks in when the client application closes and the server finishes processing requests.

12.What is the difference between null and undefined in JavaScript?

ANS:Null: A null value has been assigned to a variable. When used with the typeof operator, the result is an object. Because the programmer uses null to represent a variable with no value, we should never set a variable to null. It's worth noting that JavaScript will never set the value to null by default. Undefined: When a variable is declared but not given a value, it is said to be undefined. It's possible that a variable doesn't exist at all. When used with the typeof operator, the outcome is undefined. In JSON, it isn't valid.

13.What is a Java connection leak, and how can it be fixed?

ANS:Connection leak is a term used in Java to describe when a developer forgets to terminate a JDBC connection. When using a Connection Pool in Java programming, the most typical form of Connection Leak is encountered (such as DBCP). Close the connection and pay careful attention to the error handling code to repair it.

14.What are the various Servlet session management methods?

ANS:A session is a conversational state between the client and the server, and it might include numerous requests and answers. As a result, both HTTP and web servers are stateless, and the only way to keep a session alive is for some unique session information (session-id) to be sent between server and client in each request and response. To keep the session alive, we can utilise the following methods Authentication of Users Hidden Field in HTML Cookies Rewriting URLs API for Session Management

15.What is a Request Dispatcher, and how does it work?

ANS:RequestDispatcher is an interface for passing requests to another resource, such as HTML, JSP, or another servlet in the same application. It can also be used to add content from another source in the answer. forward() and include() are two methods of the interface ().

16.In the Spring MVC Framework, how many different ways are there to handle exceptions?

ANS:The Spring MVC Framework has the following methods for dealing with exceptions: Controller-based: The exception handler function may be defined in our controller class. Exception Handler at a Global Level: Exception handling is a cross-cutting problem that Spring addresses. HandlerExceptionResolver: Any Spring Bean that implements HandlerExceptionResolver and is declared in the DispatcherServlet's application context will be utilised to intercept and process any exception raised in the MVC system that is not handled by a Controller.

17.What benefits does Hibernate have over JDBC?

ANS:The following are some of the advantages of Hibernate over JDBC: Hibernate eliminates the JDBC API's boilerplate code. It includes features like inheritance, associations, and collections that aren't available in the JDBC API. It provides transaction management without explicitly saying so. There is no need to write a lot of try-catch code. Hibernate's HQL programming language is more object-oriented and tightly coupled to the Java programming language. Hibernate delivers greater performance than JDBC because it enables query caching, which JDBC does not.

18.What is callback ?

ANS:Callback hell is a JavaScript phenomena in which the developer tries to run several asynchronous actions at the same time. We may quickly wind up with error-prone, difficult-to-read, and difficult-to-maintain code by layering callback functions in this fashion.

19.What is the definition of a critical section?

ANS:In multi-threading, the crucial section is a piece of code that must be changed solely by one thread. Semaphore or mutex protects the vital area. There are two techniques to safeguard important sections in Java- Using Reentrant Locks and the Synchronized keyword.

20.What exactly is a numerical promotion?

ANS:Numeric promotion is the process of converting a smaller numeric type to a bigger numeric type. Byte, char, and short values are transformed to int values in this type. If necessary, the int numbers are changed to long values. As needed, the long and float values are converted to double values.

Full-stack development is a popular professional path these days. A2N Academy delivers a full-stack development course that teaches you everything you need to know to become a full-stack developer in the industry.