Backend Developer Technical Interview Questions

What Skills Does A Front

Frontend developers utilize different web technologies to change coded data into user-friendly interfaces. Many among these are Cascading Style Sheets , JavaScript, HyperText Markup Language , etc. Mentioned below are brief explanations of these technologies that frontend developers must be acquainted with.

In An Image Tag What Is The Benefit Of The Srcset Attribute

srcset is utilized when we wish to generate several resolutions of the exact image on several devices. This improves the UI. The browser will display low resolution on low-end devices, and high resolution of an image on high-end devices.

Example:

< img srcset="picture_low.jpg 480w,             picture_high.jpg 800w"     sizes=" 480px,            800px"     src="picture_high.jpg"     alt="Elva dressed as a fairy"> 

What Is The Difference Between A Process And A Thread

A process can be defined as the execution of a program, allowing users to perform the appropriate actions that are specified in a program. In other words, it means a program is in execution.

In contrast, a thread is an execution unit. It is part of a process and can be managed independently by a scheduler. A process may have multiple threads, which all execute at the same time.

Read Also: How To Ace A Project Manager Interview

How To Start A Career As A Backend Developer

If you want a career in backend developmentâbut want full support to make your dream a realityâapply to our Backend Development program. Weâll train you in the technical skills needed to become a backend engineer and coach you through every step of the job hunt, including preparing you for interviews.

In addition, we offer a promise that youâll get hired or weâll give you your money back, guaranteed! Our 110% Tuition Refund Guarantee means that if you graduate and stick with our program yet donât get job offers making at least $50,000 a year within a year, weâll pay you.

Ready to make the leap to a career as a backend developer? We canât wait to help. Apply for our Backend Developer program today!

What Is A State In React How Do You Implement It

A state is an object that stores the values of properties belonging to a component that could change over a period of time.

Here are a few features of a State –

• You can change a state as a result of a user’s action or changes in the network.
• React re-renders the component to the browser whenever the state of an object changes.
• You initialize the state object in the constructor.
• It can store multiple properties in the state object.
• this.setState is used to alter the state object’s value.
• The setState function merges the new and old state and the previous state in a shallow merge.

Free Course: Programming Fundamentals

Recommended Reading: How To Pass A Customer Service Interview

What Is Virtual Dom

• The Virtual DOM is the lightweight version of the Real DOM that React retains in memory.
• Because nothing is drawn on the screen when processing Real DOM, it is substantially slower than handling virtual DOM.
• When an object’s state changes, Virtual DOM updates only that object in the real DOM rather than all of them.

Free ReactJS for Beginners Course

What Skills Should Back

Hereâs a breakdown of the core skill set of every developer looking to ace the back-end engineer interview questions:

• Knowledge of relevant back-end programming languages
• Thorough understanding of front-end technologies such as HTML and CSS to ensure seamless integration
• Proficiency of version control systems such as Git
• Managing database administration and scaling applications
• Knowledge of data structures, APIs, and algorithms
• Experience in working with tools such as MySQL, MongoDB, Oracle, and SQL server

Don’t Miss: What Are Great Questions To Ask An Interviewer

Why Did We Utilize The Data

Generally, Data-* attributes of HTML are utilized to accumulate the custom data, which is private to the web application or page. This custom data is for personalizing the JavaScript of the user as per the user action on the web page.

These days, Data-*attributes are not advised to utilize as the user can change the attribute easily just by utilizing the browser inspect console.

Example:

What Is The Difference Between Clustered And A Non

A clustered index is a kind of index that you can use to change the order in which records are physically stored in a table. This is why tables can only have one such index.

A non clustered index is a kind of index in which the logical order of the index does not match the physical order of storing rows on a disk. The end node of such an index does not add up to the data site but consists of index rows.

Read Also: Employer Rejection Email After Interview

How To Structure Senior Developer Interviews

Remember that this interview is designed to identify candidates who have expert knowledge of the required fields and have the required years of experience as a software developer. As a result, candidates can expect to be asked some tough questions about the technical areas which they have highlighted in their resumes, like frameworks, libraries, and past projects.

Source:

Questions About Experience And Background

In addition to general questions, a prospective employer looking for a likely wants to know more about your experience and technical background. These questions assess your working styles and preferences to evaluate your previous experience:

Related: How To Pass a Job Interview

Don’t Miss: How To Analyse Interview Data

State The Difference Between == And ===

== denotes abstract equality operator, and it inspects if two values are equal or not apart from their data types. Automatically, it transforms the type of both the operands and compares them.

Example:

1=='1'     //true1==1    // true

=== denotes identity equality operator, and it inspects the values of both the operands and their data type. The outcome of the operation will be true considering both the operands are equal and have the same data type, or else it returns false.

Example:

1===1   //true1==='1'   // false

What To Look For In Senior Software Developers

A job advert for a senior software developer is likely to expect candidates to have already developed high-quality software that was aligned with user needs and business goals.

As a result, the right senior software engineer will need to have hands-on experience in software development and Agile methodologies, as well as detailed knowledge of one or more technologies.

A lead developer will also have experience working with at least some of the following: Javascript, JSON, XML, REST, NoSQL Database(MongoDB, MVC frameworks, Design Patterns, JQuery.

Additionally, a Senior software developer can be expected to:

• Work independently with little supervision
• Have excellent organizational and problem-solving skills
• Have an analytical mind with an aptitude for problem-solving
• Take the lead on operational and technical projects
• Demonstrate the ability to create and maintain relevant processes
• Be able to work with upper management to define software requirements
• Manage project timelines and priorities
• Convert business requirements into technical specifications
• Identify, prioritize and execute tasks in the software development life cycle
• Collaborate with internal teams and vendors to fix and improve products

Source: Unsplash

Recommended Reading: How To Write A Thank You Card After An Interview

Backend Developer Interview Questions: Prep To Ace Your Interview

Landing a backend developer interview is the result of so much hard work! Youâve learned the most common backend programming languages and familiarized yourself with popular frameworks, data structures, algorithms, and databases.Youâve expanded your knowledge of servers, APIs, and version control.Your resume, LinkedIn profile, and GitHub are perfect. You applied for backend jobs, which sometimes seemed like a job all on its own.

You made it: Youâve finally landed an interview! But among those feelings of excitement and relief, you might be nervous about the whole backend development interview process. You might also wonder what theyâll ask for backend developer interview questions.

If youâre anxious about interviews for backend engineer roles, youâre not alone. Itâs true that interviewing for jobs can be nerve-racking but thatâs because itâs something we donât practice often. The great news is you can do something about those nerves!

Preparing for interviews and practicing answering questions pays off. BloomTech Backend Development graduate Will Kim is proof. He learned all the technical skills needed for backend engineering jobs and tirelessly practiced for backend development interviews, which resulted in a job offer even before he graduated from BloomTech. He has some advice for aspiring backend engineers.

Differentiate Between Git Merge And Git Rebase

Assume you’re working on a new feature in a dedicated branch, and another team member pushes new commits to the master branch.

Merge

Merge is used to incorporate new commits into your feature branch. Every time you need to include modifications, this requires an extra merging commit. It taints the history of your feature branch.

Rebase

You can rebase the feature branch into master instead of merging it. This incorporates all the new commits in the master branch. It also re-writes the project history by creating brand new commits for each commit in the original branch.

This brings us to the end of Git Questions. These are some of the most important Front End Interview Questions related to Version Control.

Don’t Miss: How To Say Thanks After Interview

What Is The Difference Between Linkedlist And Arraylist

The key difference between LinkedList and ArrayList is that LinkedList exercises LinkedList Data Structure within the class with multiple variations in every element. In contrast, ArrayList falls under the category of collection framework of dynamic arrays that are distinct from standard arrays.

Also, LinkedList nodes are stored on a random basis in memory locations, while ArrayList elements are usually held in consecutive memory locations.

These are the comparison points based on Big O Notation for different actions:

What Are Form Control And Form Groups

Form Control

• It enables validation through the Form Control class.
• It produces a new instance of this class for each input field.
• These instances allow you to verify the field’s values to see if they’ve been touched, untouched, or dirty.

Form Group

• A group of controls is represented by the FormGroup class.
• Multiple control groups are possible in a form.
• If all the controls are valid, the Form Group class returns True.
• It also includes a list of all validation problems.

Recommended Reading: What To Do In An Interview For Your First Job

What Is Promise And Explain Its States

As an alternative to callbacks in JavaScript, promises are used to handle asynchronous operations. In addition to handling multiple asynchronous operations, they provide better error handling than callbacks. Promises can be a better way for a user to read the code effectively and efficiently, especially when that particular code performs multiple asynchronous operations. The Promise object represents the result of an asynchronous operation and the resulting value. The promise is in one of the following states:

• Pending: In its initial state, neither fulfilled nor rejected.
• Fulfilled: Indicating that the operation was successful.
• Rejected: Indicating that the operation failed.

In Html How Do You Separate A Section Of Text

In HTML, you use the following tags to divide a chunk of text:

< br> tagIt’s a character that’s used to break up a line of text. It transfers the text flow to a new line by breaking the existing line.

< p> tagThis tag is used to create a text paragraph.

< blockquote> This tag is used to indicate big quoted passages.

Don’t Miss: How To Write A Thank You Letter For An Interview

When Is It Best To Use Net Web Forms Instead Of Aspnet Mvc

An interviewer can ask this question to gauge your experience with web development platforms and your preferences for creating applications. Addressing both .NET Web Forms and ASP .NET MVC can emphasize your grasp of different forms and when you should use them.

Example answer:Many developers use ASP .NET MVC because of its ability to break down applications into discrete models, views and controllers, which makes testing them easy. However, the .NET framework and its Web Forms might be preferable to developers who want to create simple applications rapidly, as using .NET Web Forms doesn’t require them to learn new coding or programming languages.

Where Are The Answers

Sooner or later I will complete it with the relative answers. Feel free to contribute, it would be highly appreciated!

Law of Demeter

The Law of Demeter states that each unit should have only limited knowledge about other units and it should only talk to its immediate friends .Would you write code violating this principle, show why it is a bad design and then fix it?Resources

Active-Record

Active-Record is the design pattern that promotes objects to include functions such as Insert, Update, and Delete, and properties that correspond to the columns in some underlying database table. In your opinion and experience, which are the limits and pitfalls of the this pattern?Resources

Data-Mapper

Data-Mapper is a design pattern that promotes the use of a layer of Mappers that moves data between objects and a database while keeping them independent of each other and the mapper itself. On the contrary, in Active-Record objects directly incorporate operations for persisting themselves to a database, and properties corresponding to the underlying database tables. Do you have an opinion on those patterns? When would you use one instead of the other?Resources

Billion Dollar Mistake

Why is it often said that the introduction of null is a “billion dollar mistake”? Would you discuss the techniques to avoid it, such as the Null Object Pattern introduced by the GOF book, or Option types?

Inheritance vs Composition

Goto is Evil

Robustness Principle

You May Like: Interview Questions For Nonprofit Executive Director

What Is The Packagejson File

The package.json file is the heart of a Node.js system. This file holds the metadata for a particular project. The package.json file is found in the root directory of any Node application or module

This is what a package.json file looks like immediately after creating a Node.js project using the command: npm init

You can edit the parameters when you create a Node.js project.

Full Stack Web Developer Course

To Develop A Project From Scratch What Technologies And Languages Would You Need Or What Skills A Full Stack Developer Should Have

A full-stack developer must be familiar with the following:

• Programming Languages: Full-stack developers should be competent in more than one programming language, such as Java, Python, PHP, Ruby, C++, etc.
• Front End technologies: You should be familiar with front-end technologies such as HTML5, CSS3, JavaScript, etc. Knowledge of third-party libraries such as jQuery, Ajax, Angular, ReactJS, etc., is also important.
• Frameworks: This requires proficiency in a variety of development frameworks, including Spring, Spring Boot, Django, MyBatis, PHP, Hibernate, and others.
• Databases and caches: As a full stack developer, you should also know about various DBMS technologies like MySQL, SQLite, Oracle, and MongoDB. It is helpful to have a basic understanding of caching mechanisms like redis, memcached, varnish.
• Design Ability: Having a good understanding of design is also important if you wish to become a successful Full-Stack web developer. Moreover, the person should be aware of the principles of prototyping and UX/UI design.
• Server: Experience with Apache or NGINX would be beneficial. Good knowledge of Linux helps enormously when administering servers.

Don’t Miss: How To Answer Tell Me About Yourself In An Interview

Explain The Difference Between Git Pull And Git Fetch

Git Fetch

git fetch -all

Git Pull

• Git pulls new data and integrates it with the current working files, updating the current HEAD branch with the latest modifications from the remote server
• It attempts to combine remote modifications with those made locally
• Command – git pull origin master

FREE GIT Training

Define And Explain These Nine Server Response Error Codes: 200 201 204 301 400 401 404 409 And 500

Your interviewer typically asks this when they want to know the depth of your error knowledge. Address each part in order, explaining what the code means and what caused the error.

Example: 200 means OK and everything went well. A 201 Created’ message means the system created a resource at the client’s request. A 204 No Content code means the server didn’t send back a status. A 301 Moved Permanently message means a client-triggered action changed the resource URI. A 400 Bad Request error refers to a client-side error.

If the client doesn’t provide the correct authentication, you see a 402 Unauthorized code. A 404 Not Found return means it didnt find a mapped resource. An inconsistent or impossible state returns code 409, Conflict. Server-side errors generate code 500, described as, Internal Server Error.”

Related: 20 Database Testing Interview Questions

Don’t Miss: How To Prepare For Devops Interview

What Is Semantic Html How Does It Work

• Semantic HTML is a type of coding.
• It is the use of HTML markup to emphasize the content’s semantics or meaning.
• Consider the following scenario: The < b> < /b> tag is not used for bold statements in semantic HTML, while the < i> < /i> element is used for italic.
• Instead, you use the < em> < /em> and < strong> < /strong> tags.