How to ace the coding interview — Jessica’s Career Tip of the Week

Coding interviews are an essential part of any software engineering interview process. They are a great way for employers to know if a candidate is the right fit for their company by testing the candidate’s fundamental programming knowledge. Most coding interviews cover different applications of data structures and algorithms, and although these may not be commonly used on the job, they are a great way to see how an applicant thinks and how they will go about solving problems when they are actually on the job.

In the actual interview, the coding problems are done on a whiteboard, with no access to a compiler to check if your program is running correctly. For this reason, it is more important to know how to apply data structures and algorithms to the problem rather than trying to get the syntax of the programming language correct. When given a problem, you first want to read the problem carefully and ask any and all questions you have. Once you’ve understood the problem, explain the first solution that comes into your head, even if it isn’t the most optimal one. From there, you can derive the optimal solution and explain your thought process to the interviewer. If they agree that your solution is the most optimal, you can write the solution down.

The best way to start studying for coding interviews is to take a data structures and algorithms course as well as a fundamental programming course in any language (preferably Java, Python, C and C++ as they are most commonly used). Most software-related majors will take a data structures and algorithms course sometime during their program and taking this as early as possible will benefit you the most. Keep in mind that there are a large number of data structures and algorithms to learn about, with the main ones being Arrays, Strings, Linked Lists, Trees, Graphs, Binary Search and sorting algorithms, so a course can help with this. These courses also provide you with much of the theoretical and hands-on knowledge needed to excel in programming interviews.

Once you have a good understanding of the common types of data structures and algorithms as well as knowledge of how to apply them in a programming language, it is time to actually practice. Practicing is the most important part because it is easy to lose track and forget to do so. Some great websites that have practice coding interviews are leetcode and hackerrank. Make sure you practice as often as possible, not just before interviews, and practice with friends where you can take turns interviewing each other to simulate the interview experience better.

Finally, knowing how to evaluate your solution is an important part of the interview. Space and time complexities are analyzed through the use of big O notation, which is a concept that is taught in many data structures and algorithms courses. Once you finish your solution, whether it is in an interview or during practice, you should be able to explain what the big O of the space and time of your solution is.


  • Cracking the Coding Interview A great book to brush up on data structures and algorithms knowledge
  • A website to practice popular coding problems
  • Another website to practice coding problems
  • YouTube Great for coding problem tutorials and learning more about data structures and algorithms

*This blog was written by Peer Career Coach, Prashant Mokkapati