CODING INTERVIEWS: Advanced Guide to Help You Excel at Coding Interviews

By Olivia Miller

Interviews are stressful and can overwhelm even the most experienced candidates. Whether this is your first coding interview or your tenth, you are still likely to be a bag of nerves, but given that this is an important step in getting the job you dream of, it's important that you don't fluff it at the first step.

Programmers a

• Language: English
• Publisher: Olivia Miller
• Release date: Oct 23, 2023
• ISBN: 9798868941924

Book preview

Introduction

Interviews are stressful and can overwhelm even the most experienced candidates. Whether this is your first coding interview or your tenth, you are still likely to be a bag of nerves, but given that this is an important step in getting the job you dream of, it’s important that you don’t fluff it at the first step.

Programmers and developers consider the coding interview one of the toughest interview rounds because it doesn’t just assess their ability to make decisions, solve problems, and write code; it also assesses their intelligence, logical thinking, and interpersonal skills.

Before you attend any coding interview, you need to be fully prepared to face anything the interviewers might throw your way. Cracking coding interviews is not as easy as getting through other job interviews because you are working with complex problems, algorithms, and scenarios that you can only solve with strong logical and technical skills.

The old saying, practice makes perfect, has never been more true than in the coding interview, and this guide is designed to help you be as prepared as possible.

Let’s not waste any more time; it’s time to crack this interview.

Chapter 1

Preparing for the Interview

Preparing for a coding interview is no mean feat. Sure, the fact that you’ve actually got an interview is exciting and just a bit terrifying, but you don’t have to spend days or weeks slogging through hundreds of practice questions.

You might not have prepared properly if you’ve already been through dozens of interviews and gotten nowhere. If this is your first coding interview, this guide has you covered, and we’ll start with a series of tips that tell you how to prepare for it, not just the technical rounds, but the non-technical rounds too.

Let’s dive in.

Determine the Format the Interview Is Being Held in

There are several formats a coding interview can take, so you must determine which format yours is in to ensure you are fully prepared. These are the most common formats:

Quiz Format

Interviews may occasionally be in the form of a quiz designed to quickly clear the non-technical or weaker candidates from the pack. These quizzes are a series of structured questions with very clear answers, enabling them to be asked by non-technical people, recruiters, or automated graders. They are usually very early in the interview process.

Some examples of questions include:

What is the bubble sort algorithm’s time complexity? The answer is O(n²)

What is 4 & 5? Provide the answer in binary. The answer is 4.

Online Coding Assessment

These are also done quite early in the process, like the quiz format. Typically, the candidates are provided with an algorithm problem. They are given fully informed outputs and inputs and must then use the provided online coding interface to write the code needed to solve the problem. You can get some practice with these by heading to LeetCode or HackerRank online. Leetcode is good for getting practice in solving problems in online formats, but HackerRank requires you to write the code, so it reads from stdin and points to stdout; if you aren’t familiar with APIs, this can cause you a few problems.

Take Home Assignments

These are rarely used as a form of an interview. Over the years, one subject of many debates has been whether algorithm questions can truly assess a person’s abilities, as algorithms aren’t relevant skills for a coding job’s day-to-day duties. When the take-home assignment format is used, it helps address the algorithm interview’s shortcomings by allowing candidates to do larger projects and show off their skills in software design.

However, it is a time-consuming format for both the candidates and the hiring company. That’s why it is rarely seen unless the hiring company is small or is a startup and only has a few interview candidates. Some examples of the assignments you might be asked to do are:

Design and build a snake game

Design and build a Kanban app

Design and build an app for listing flights

Phone Screen Interviews

These are a more common interview format; all candidates will undergo at least one phone-screen interview throughout the process. You will be invited to talk to an interviewer over a phone or VoIP call, where they will ask you a question. You need to use an online collaborative editor the work on the answer.

Whether the editor supports code execution or not, you won’t usually be asked to execute your solution, so don’t rely on that to let you know if your solution is right. The interview format will differ from role to role. Most companies prefer to do collaborative editing on CoderPad because it supports running the code. You may be asked to fix your solution to ensure it runs. If you are attending a front-end interview, you might be asked to use CodePen, so take the time to learn the interfaces for both of these environments.

Later, we’ll talk about what you should do before, during, and after these interviews.

Onsite Interviews

Another frequently used interview format, onsite interviews, are normally the last step after the wrong candidates have been weeded out. These are where the final candidate is chosen. If you make it to this stage, you will need to attend an in-person interview; overseas candidates may even be flown in and provided with accommodation.

The onsite interview will normally have several rounds, including coding, behavioral, and system design. And because this is an onsite interview, you may even be asked to solve a system design or algorithm design question on a whiteboard. You might even be asked to bring a laptop and solve a coding problem at some point during the interview.

Suppose you are interviewing at a smaller company, typically non-public. In that case, you will likely be asked to use your own laptop anyway, so ensure your development environment is set up in advance. And if lunch is provided, you could even chat with other employees about the company culture.

Choose a Programming Language

What is the best programming language to use in your coding interview? And does it even matter which one you use?

The short answer to that is yes, it does matter.

Most companies will allow you to use a programming language of your choice unless they use a specific one. The only real exception to that is Google, where candidates must choose between Python, Java, JavaScript, and C++.

However, the language you choose can impact your performance more than you would believe possible. This is why choosing the right programming language at the start of your interview preparation is critical, as is using it regularly to get used to it.

There are three things to consider when you decide which language to use:

1.  Is It Suitable for the Interview?

Some languages are more suitable than others for interview situations. Typically, Java, Python, and other high-level languages provide the standard data structures and library functions that allow you to solve code more easily.

Most people tend to choose Java or Python, while others go for C++, JavaScript, or Ruby – all of these are popular languages and relatively intuitive to learn. It is recommended that you ignore low-level languages, such as Go or C, as they don’t have the standard data structures and library functions and may even require memory to be managed manually.

Python is one of the most popular, and unless the company you are interviewing with specifies another language, you won’t go too far wrong if you choose it. Python is one of the easiest to learn and has a massive library full of data structures and functions, not to mention its APIs are consistent and work on different structures. In fact, because its syntax is simple, Python allows you to achieve quite a lot with not a lot of syntax.

Java isn’t a bad choice but requires you to keep having to declare types in your coding solutions; this means a lot more typing with no real benefit for the interview. While this may not seem to be an issue, it will be when you have to do a whiteboarding exercise at the interview! And C ++ is similar to Java in reasons for choosing or not choosing it.

Recommended: Python, Java, C++, JavaScript

Acceptable: Ruby, Go, PHP, Swift, C#, Kotlin

Avoid: Erlang, Haskell, Matlab, C, Perl, Assembly

Always choose the language you are most familiar with unless the company you are interviewing with states a specific one, which brings us to the next point.

2.  How Familiar You Are With the Language

It is always recommended to choose a language you know and use all the time rather than trying to learn a new one for an interview. In fact, if you only have a short time before your interview, choosing a new language to learn is not a good idea. Programming languages take time to learn and master; you need all the spare time you have to master data structures and algorithms and revise them. If you already have experience with a popular mainstream language, there is no sense in wasting time on anything else. Especially not if it is just for an interview.

Good Reasons For Learning a New Language:

The company you are interviewing with requires