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Manuel Aparicio
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IT-related Interview Questions


The questions for an IT interview can be daunting and highly challenging. As a matter of fact, 90% of job seekers in the IT Industry fail the interviews. The fail/pass ratio can be even higher depending on the specific role. Hence, it doesn't come as a surprise the book Cracking the Coding Interview was a total success. On top of that, passing a technical interview can be even more difficult if you're a junior developer. That's why it's so important to prepare yourself for it diligently. In this way, you must understand what the interview is trying to test.

The IT industry involves many roles to deliver the best possible solutions. Each is in charge of particular tasks, requiring extensive yet specific knowledge. Technical and soft skills vary for full-stack dev, DevOps, QA Automation, or UI/UX design. Thus, questions and the conduction of these interviews can change a lot. This article will cover some of the most commonly asked questions in IT-related interviews. Plus, we'll give tips to ensure you get the best results. Let's go!

How To Prepare for an IT Interview?

One of the most important things to do before an interview is to read the job description carefully. Make sure that you fully understand the position you are applying for! Also, ensure that you can ask meaningful questions to the interviewer. This approach will let you prove you have the required skills to perform your tasks. By understanding all the requirements, you'll be able to do targeted exercises in advance.

Practice is crucial to ace the interview! Rehearse out loud the answers to questions you might receive. Also, consider the languages, libraries, and structures you'd use to complete the tasks. Besides, it's important to rehearse how you'd respond to general questions. These questions can be about yourself and your past experiences.

Keep in mind that you need to understand the questions asked to answer them accurately. Most interviewers want to know your problem-solving skills, teamwork ability, and coding skills. Plus, they want to hear if your background and current abilities align with the vacancy. Chances are that only some of your previous jobs and skills can relate to the specific role. Make sure you highlight them during the interview without being dishonest.

You can take advantage of different platforms to practice your coding skills. Some include Leetcode, Pramp, AlgoExpert, Interviewing.io, and InterviewBit. Yet, it isn't just about coding skills! You're also very likely to receive questions about behavioral and system design questions. Managing your time correctly when practicing for those types of questions is vital. It all depends on the seniority level of the vacancy.

IT Related Interview Questions

What are the Types of IT Interview Questions?

Let's talk about the questions you may have during the interview.

1. Coding Interview Questions

Coding is one of the pillars of almost any job in IT. Interviewers need to know that you can complete tasks and meet deadlines. In most cases, these questions relate to data structures and standard algorithms. If you are applying for a back-end dev role, you need a solid understanding of different edges. Some skills include strings, maps, arrays, queues, sets, stacks, graphs, recursion, and trees.

Yet, front-end dev needs vast knowledge of HTML, CSS, JavaScript, and some of its libraries. It's worth noting that several roles generally don't need coding experience. For example, UI/UX, Software Tester, Project Manager, and SEO Specialist. Yet, knowing the basics is a plus, as it improves communication with developers.

Coding questions can also be in the form of practical exercises. Here are some examples:

● How do you reverse a given string in place?
● How to get the matching characters in a string?
● How do you check if a given string is a palindrome?
● Implement the Fibonacci series (Recursion, Generators, lists).
● How do you swap two strings without using a third variable?
● How do you check if two strings are a rotation of each other?
● How do you perform preorder traversal in a given binary tree?
● How do you find the biggest and smallest number in an array?

2. System Design Interview Questions

System Design is an integral part of software engineering. It encompasses the entire development process, from requirements analysis to implementation. Also, it involves planning before any coding or development takes place. System Design determines the system's architecture, structure, and components. The interviewer needs to know you can make significant contributions. You need to understand some concepts to prepare for a System Design interview. Some include load balancing, API Design, Database Sharding, and SQL and NoSQL Databases. Also, handling CDN, Consistency Patterns, and Latency can help.

You may have to explain how to build scalable systems if applying for a senior position. They might ask about your path to creating platforms like Facebook or Youtube. Make sure you go into detail when describing functionalities, transitions, and database schemas. The interviewer wants to see your ability to understand a problem and design a solution. It's not only about the final answer but how you get there.

3. Behavioral Interview Questions

Behavioral questions are critical for any position in IT. These are non-technical; hence there are many ways to handle them. Yet, these intend to assess the same traits and qualities of you as a person. Among the most desired qualities, there is leadership, empathy, and initiative. Also, the ability to handle stress, solve conflicts, and give feedback is helpful. Interviewers often ask about past experiences working in related roles. They might also ask about your favorite projects, intending to know you better. Some of the questions they ask also receive the name "situational questions." Here, you'll need to explain how you'd handle a difficult situation.

A practical way to answer behavioral questions is by using the STAR method. This method starts by using stories from your previous roles. Then, you'll need to provide a list of steps you have to take to give the correct info. STAR is an acronym for Situation, Task, Action, and Result. Here's what you need to know about those steps:

Situation: Present the problem with some context.
Task: Explain what needs to get done and why.
Action: Describe what you did to solve the problem.
Result: Illustrate the outcome.

Most Common Questions in IT Interviews

Object Oriented Programming Interview Questions

As you may know, Object Oriented Programming (OOP) is a fundamental paradigm in most programming languages. Plus, it is very often used to build real-life applications. Hence you also need to be familiar with it. Here are some common questions you may encounter:

● What's overload?
● What is inheritance?
● What is polymorphism?
● What are the solid principles?

Front-End Development Interview Questions

● What are closures in JavaScript?
● What is the difference between let and var?
● What is the difference between undefined and null?
● How can an HTML element be accessed using JavaScript?
● Can you tell me about your experience with React Hooks?
● How do you create a synthetic event in React?
● How do you empty an array in JavaScript?
● What is the Strict Mode in JavaScript?

Back-End Development Interview Questions

● What are modules in Node.js?
● What is a package .JSON file?
● What are streams in Node.js?
● What is the control flow function?
● What is the test pyramid in Node.js?
● How to create a simple Express.js app?
● What are the two types of API functions in Node.js?
● What is a singleton pattern? What can you do with it?

Control Systems Interview Questions

● What's the difference between centralized and distributed control systems?
● What's the difference between Git Fetch and Git Pull?
● What is GIT Branching?

Web Design Interview Questions

● Explain CSS Specificity.
● Explain the CSS Box Model.
● What is responsive web design?
● Name different ways to position aspects in CSS.
● What do you understand by pseudo-elements?

IT-related Interview Questions

7 Tips for IT Work Interviews!

● Make sure you fully understand the questions. It's OK to ask for clarification!
● Emphasize how your previous roles can relate to the one you're applying for.
● Think out loud when answering questions or solving coding problems.
● Let them understand your reasoning behind finding a problem's solution.
● Ask for further information about the project to show you're interested.
● Research the company to understand its values before the interview.
● Be honest!


There are three main aspects that you need to consider to ace an IT interview: Coding, System Design, and Behavioral. It would be best if you manage your time according to the role you're aspiring for. Remember that most high-level positions will focus on system design and behavioral questions. If you're applying for an entry-level job, focus on coding questions. IT interviews can be challenging and seem intimidating. Luckily, plenty of resources are available for you to prepare for them! If you are applying for the correct position and you study correctly, you're halfway there. We wish you the best of luck in your next IT interview!