Top 45 Software Engineer Interview Questions: Cracking the Coding Interview

Oct 29, 2021

Knowing what software engineering interview questions you can expect in your upcoming interview rounds can give you a big leg up!

Software engineering jobs are incredibly competitive. That means you're likely up with more qualified applicants than ever before.

You can ace the interview and land the job by preparing for whatever questions come your way.

The roles and responsibilities of a software engineer differ dramatically based on the company.

Because of the variation in software development life cycle, job duties can be intimidating walking into a job interview.

To help you prepare, we spoke with dozens of software engineering candidates, current engineers at FAANG companies, technical managers, and hiring managers to help create this in-depth look at software engineer interview questions.

Below is our list of the top 30 software engineer interview questions you will get asked.

Table of Contents:

Abstract  by  Nikita Kozin

System Design

When it comes to day-to-day software development, candidates will rely primarily on their coding skills. However, the best software engineers also have strong system design skills.

System design refers to developing software architecture, product design, interfaces, data, and more for a technical system according to requirements.

Expect one or two system design interview questions like those listed below. Often, companies will ask you to design a system that solves a real challenge for the company, so be sure to read your target company's engineering blog before interviewing.

This, and the structure of the system design interview, which tests a candidate's knowledge, problem-solving, and high-level thinking, makes this round a great test of how a new software engineer will perform on the job.

The best software engineering candidates have a comprehensive knowledge of distributed systems, from component-level decisions to APIs and how to scale a system reliably and efficiently.

Check out our system design interview course to help you ace any system design question that comes your way.

  1. Design a reservation and payment system for a parking garage (Watch answer).
  2. How would you design and implement a password checker given specific requirements for the password?
  3. How would you create a relational schema for a calendar application? See our example answer to this question here.
  4. Design a service that supports uploading and tagging images to a travel site.
  5. How long does it take to send a signal from one computer to all other computers? Watch an answer to this question here.
  6. Design a visual landmark recognition system.
  7. Design an app to be used in an amusement park. See our example answer to this question here.
  8. Design a typeahead box for a search engine. See our example answer to this question here.
  9. How does Alexa process voice commands?
  10. Design Twitter. Watch a sample answer to this question here.
  11. Design Facebook Messenger. Watch our co-founder, Jacob, answer this question below.

Data Structures

The foundation of the software development process is in data structures and algorithms, hence the popularity of leetcode-esque coding questions. The best software engineering candidates understand how data structures work and practical use cases for each.

Therefore, many technical interview questions/coding exercises focus on your knowledge of data structures and appropriate algorithms (covered next).

The best way to prepare for these questions is to review the following primary components in data structures:

Once you've reviewed the basics, practice a few self-guided technical interview questions to test your skills.

  1. Store a list of numbers as a single number. See our example answer to this software development question here.
  2. How do you split up a machine learning dataset for training, evaluation, and testing? Watch an example answer to this question here.
  3. You are given a table with varying distances from various cities. How do you find the average distance between each of the cities?
  4. Determine if the given Binary Tree is a BST or not.
  5. Find k-th smallest and k-th most prominent element in BST.
  6. Determine if an array from 1..n has a duplicate in constant time and space.
  7. If you had a vector with a lot of values in it, of which most are zeroes, how would you design a data structure to represent it?
  8. Construct a Binary Tree from Ancestor Matrix
  9. Check if two given binary trees are identical or not
  10. Sort a Doubly Linked List using Merge Sort
  11. Find number of rotations in a circularly sorted array

Algorithms

Like data structures, engineering algorithms are another fundamental piece of the software development process. Many software engineer interview questions will be focused on them. An algorithm is a set of rules or procedures that your system or program performs during its operation.

When it comes to the software engineering interview, your hiring manager will expect you to identify and work with various algorithms that are most appropriate to whatever problem you're given.

Algorithm and data structure questions are helpful, concrete tools hiring managers use to assess a candidate's problem-solving and experience.

Be sure to review standard algorithms for searching, sorting, and notoriously-difficult dynamic programming problems. You can find many examples of these algorithms in our SWE interview course.

  1. Write a pair of functions to serialize and deserialize a list of strings. Watch an answer to this question here.
  2. Iterate through a list of trades and return a list of buy/sell pairs and the overall profit of the transactions.
  3. Merge Intervals. See our example answer to this question here.
  4. Print left view of a binary tree. See our example answer to this question here.
  5. Given an nxn grid of 1 and 0s, return the number of islands in the input. See our example answer to this question here.
  6. How many hoops will a VM in one region have to go through to talk to VM in another region?
  7. Find the minimum cost to reach the last cell of the matrix from its first cell.
  8. Find the index of 0 to replace to get the maximum length sequence of continuous ones.
  9. If you had a vector with many values in it, of which most are zeroes, how would you design a data structure to represent it?
  10. Write a program to print the maximum positive sequence in a given array.

Product Strategy

Don't worry - product strategy is probably not part of your software engineering interview. However, it is still critical for companies that their software engineers understand the product strategy that ultimately drives the software development. Having an understanding of:

  • Market Analysis: Who your target company's users are and what they want.
  • Competitive Analysis: What the competition looks like.
  • Product Strategy and Roadmap: The company strategy and product pipeline may look like this.

This will give you quite an edge if you're interviewing with an ultra-competitive tech company.

If we've piqued your interest, you can check out a few Product Strategy lessons in our Product Management interview course.

  1. Should Facebook consolidate its messaging apps? See our example answer to this question here.
  2. Should Apple go into modular phones? See our example answer to this question here.
  3. Why is Android strategically important to Google?
  4. If you were the CEO of Microsoft, how would you increase usage for Internet Explorer? Watch a sample answer to this question here.
  5. How should Google enter the streaming space?

Behavioral

At a certain point during your software development or engineering interview, you will likely be asked some behavioral questions.

As the name suggests, behavioral interview questions are used by interviewers to evaluate your past behavior and performance in your previous positions.

Behavioral interview questions are also a great way to determine if you would mesh well with the company culture.

These kinds of questions can be difficult for some. Therefore, we recommend using a framework such as STAR to ensure that you're answering your behavioral interview questions as best as possible.

Here are some of the best examples of behavioral questions you can expect:

  1. Tell me about a time you had to make a decision to make short-term sacrifices for long-term gains. Watch a sample answer to this software development behavioral question here.
  2. Tell me about the most complex project you've worked on. Watch a sample answer to this interview question here.
  3. If you have to work on 5 different projects, how do you prioritize?
  4. How do you structure 1:1s?
  5. Tell me about a situation where you had to solve a difficult problem.
  6. If given a chance what would you have changed anything about a project what would it be and why ?
  7. Tell me about a time where you had to lead your team through a significant change (this could be a reorganization or process). How did you handle it?
  8. How should Google enter the streaming space?

How Top Tech Companies Assess Software Engineering Candidates in 2022

Abstract  by  Oleg Shcherba

Now that we've gone over the types of software engineer interview questions you'll face, we should cover how hiring managers in 2022 assess their software development candidates. Specifically, here are the primary skills or dimensions that software engineering interviews evaluate.

Technical Skills

It should come as no surprise that the fundamental dimension of software development interviews centers on assessing a candidate's technical skills.

Hiring managers seek candidates with knowledge and experience in the programming languages, frameworks, cloud services, etc., used at the company. Not only that, hiring managers to seek candidates who can write clean code that is easy to maintain.

To evaluate the technical skills of a software engineer, hiring managers ask many previously listed technical interview questions. As a result, there's a good chance that SWE candidates will need to complete coding exercises during their interviews.

The technical skills being evaluated will also include your experience with things like the agile software development process, project management tools, and the software development life cycle more generally.

Problem-Solving Skills

While candidates will never get an offer without the necessary technical skills, make no mistake: problem-solving is a software engineer's most important skill set.

A software developer or engineer is responsible for developing complex systems to address complex problems. Such endeavors require tremendous problem-solving skills, as you can imagine. Not only that, but high-level problem-solving skills also allow a software developer to spot or anticipate bugs while finding new ways to write faster code, no matter their programming language.

Problem-solving is the most important and the most challenging aspect of software development and being a software engineer. Therefore, one way or another, nearly all the interview questions your hiring manager will ask are meant to evaluate some component of your problem-solving abilities.

Abstract  by  Oleg Shcherba

Communication Skills

However, what might not be so unsurprising is the emphasis on the communication skills of software development candidates.

While most of your work as a software developer or engineer will undoubtedly be writing code, software developers also need to write emails, slack messages, documentation, and more while communicating with co-workers and other teams.

Your interviewer may assess these skills with questions such as "How do you explain engineering concepts to non-technical team members?"

Culture Fit

Software engineers are some of the most sought-after and highest-paid workers in today's economy. But the other side of this coin is that the competitive landscape at the top tech companies is fierce.

FAANG companies like Google, for instance, receive millions of applications a year. As such, culture fit is more important than ever for hiring managers.

It's simply not enough to have the technical skills necessary for the role. In addition, candidates will need to mesh well with the corporate culture and the other employees at the company.

Generally speaking, hiring managers will ask behavioral questions such as "why are you a great match for this role?" to assess culture fit.

If you're interested in preparing for this interview, check out our Tech Company Core Values article.

Software Engineering Cheat Sheet

Be sure to check out Exponent's software engineering interview cheat sheet. Regardless of your programming language, it covers all the significant concepts and tips you'll need to ace your SWE interview.

More Software Engineering Interview Prep

While studying commonly asked software engineering interview questions is crucial, you'll need some more interview prep to boost your chances. Fortunately, you can find plenty of different resources and types of resources at Exponent to help you practice for your upcoming SWE interview:

💬 Get prepared with example software engineering interview questions

📖 Read through our Software Engineering company interview guides

👯‍♂️ Practice your behavioral and system design skills with our mock interview practice tool.

👨‍🎓 Take our complete Software Engineering interview course.

Anthony Pellegrino

I'm Tony, a freelance journalist, writer, and content marketing strategist. I write about interview prep and career planning for Exponent, but I also write about climate change, tech, and, politics.

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