Common Coding Interview Mistakes and How to Avoid Them

Are you getting ready for a technical interview at a dream company like FANG? Are you anxious about making the best impression and passing the coding test? Don't worry; this article is here to help you avoid common coding interview mistakes and ace the interview.

Understand the Question Before Starting to Code

One of the most common mistakes in coding interviews is not understanding the question before starting to code. Rushing to write code without fully understanding the problem can lead to incorrect solutions and wasting time.

To avoid this mistake, make sure to read and understand the question carefully. Ask the interviewer any clarifying questions you may have, and take the time to plan your approach before writing any code. Consider different input scenarios and edge cases, and decide on the best data structures and algorithms for the problem.

Don't Jump Straight to Writing Code

Another common mistake in coding interviews is jumping straight to writing code without a clear plan or pseudocode. Writing code without a plan can result in confusion and costly mistakes.

Note that interviewers expect you to explain your thought process and approach to the problem, not just write working code. So, take the time to plan and write pseudocode before typing in the code. Pseudocode is helpful because it allows you to get a clear understanding of the problem and your approach to solve it without getting bogged down in language-specific syntax like loops and variables.

Test Your Code with Test Cases

Another mistake that many candidates make is not testing their code with test cases. This is a big mistake since it can lead to missing edge cases, producing incorrect outputs, and wasting time with debugging.

To avoid this mistake, test your code with different input scenarios and edge cases. Ensure that it returns the correct output for all cases. Additionally, test cases help to clarify your approach and indicate if any edge cases weren't identified earlier that you must include.

Don't Assume Inputs and Outputs

Assuming inputs and outputs can lead to unexpected results and errors in your code. Interviewers may give inputs that you didn't anticipate when solving the problem. You may not be able to see the hidden test cases if you assume inputs and outputs.

Make sure to clarify the inputs and outputs with your interviewer before starting to code. This way, you can be sure you correctly define the problem and understand what the problem requires. Even after clarification, check for any unanticipated inputs and outputs through testing your code.

Handle Errors Gracefully

Another common mistake is not handling errors gracefully. You must write code that can handle invalid inputs and outputs without crashing. Not doing so can give a bad impression and indicate that you're not an experienced developer.

To avoid this mistake, ensure that you write code that can handle invalid inputs and outputs gracefully. You can do this by including error handling in your code, using try-catch blocks or assertions. These will help to detect errors upfront and allow you to recover gracefully from failures.

Don't Get Stuck on a Problem

It's crucial to show your problem-solving skills during an interview. However, don't get stuck on a problem and waste too much time on it. Remember, you're only given a limited amount of time to solve the problem during the interview and must demonstrate good use of that time.

If you encounter a problem that you're not able to solve, move on to the next one instead of getting fixated on it. This shows an important problem-solving skill - knowing when it's best to move on.

Don't Be Afraid to Ask Questions

Interviewers want to see your problem-solving and communication skills. Don't be afraid to ask questions if you don't fully understand the problem or have questions about the company or its products. Also, don't be afraid to ask for clarifications as you write code if necessary.

Asking questions demonstrates that you're taking the time to understand the problem and are interested in the company. This also shows that you can communicate effectively and possess important interpersonal skills, e.g., asking good questions.

Do Your Research

One of the biggest mistakes in interviews is not knowing what to expect or not having enough preparation. You need to understand the level of detail expected at the interview and the company culture to ensure you're the best match.

Research the company, its products, culture, and interview process. Make sure you know about their products or services, their markets, key competitors, and their tech stack. Understanding the types of questions asked and common coding interview topics will help you better prepare.

Practice, Practice, Practice!

Coding interviews are competitive, and you need to put in a lot of work to be successful. Practicing coding problems can help you improve your problem-solving skills and get comfortable with different data structures, algorithms, and languages.

You can practice coding problems online, participate in coding competitions, or join practice communities. Practice different types of questions and eventually analyze the solutions or coordinate with others. That way, you'll strengthen your problem-solving skills, and you'll be mentally prepared for any problem.


Coding interviews can be daunting, but there are many ways to prepare for them. By avoiding common coding interview mistakes and practicing, you'll be more proficient in your problem-solving skills and better equipped to demonstrate your technical abilities.

Just remember to take your time understanding the problem, don't jump straight to writing code, test your code thoroughly, and be open to feedback. With these tips, you're poised for success during any coding interview!

Editor Recommended Sites

AI and Tech News
Best Online AI Courses
Classic Writing Analysis
Tears of the Kingdom Roleplay
Deep Graphs: Learn Graph databases machine learning, RNNs, CNNs, Generative AI
Cloud Data Fabric - Interconnect all data sources & Cloud Data Graph Reasoning:
Customer Experience: Best practice around customer experience management
NFT Sale: Crypt NFT sales
Dev Use Cases: Use cases for software frameworks, software tools, and cloud services in AWS and GCP