Introduction
Hiring software engineers is an exceptionally time-consuming and an expensive process for many organizations. The dilemma is, how can someone know if the candidates they’re considering for their company are competent enough? Will they be a good fit for their team? The kinds of issues software developers fix are long and complex. How can you ensure you hire the right person for your team? Whiteboard coding interviews can help you in ensuring this!
Whiteboard programming interviews have become standard practice for software engineers. Several big tech companies have their versions of coding whiteboards in their interview cycles to ensure they hire the right candidate.
What is a whiteboard coding interview?
Whiteboard coding interviews are a style of interview question that assesses a potential hire’s technical and non-technical skills. The question can either be a data structure and a specific algorithm problem or a more abstract systems design and architecture-based question.
During a whiteboard programming interview, interviewers share a coding problem with candidates and ask them to outline their solutions on a whiteboard.
Why conduct whiteboard coding interviews?
Given the competition and the many job applicants, whiteboard coding interviews are a great way to screen out candidates who don’t meet hiring organizations’ criteria.
Organizations must check competency when hiring for a software developer position to establish baseline confidence. They cannot filter good candidates just from a single interview technique. However, using the right interview techniques can help you ensure certain qualifications.
Whiteboard interviews push both the interviewer and the candidate to think at a higher level. Without the crutch of development tools, syntax highlighting, or automatic error checks, the focus shifts entirely to the problem itself.
But here’s the thing — a whiteboard interview isn’t about testing whether a developer has every bit of syntax memorized. In fact, it’s the opposite. Stripping away those details creates space to zero in on the real challenge: understanding and solving the problem.
What are the different types of whiteboard coding interview questions?
Below are some of the most common types of whiteboard coding interview questions.
Algorithmic questions
These questions assess a candidate’s problem-solving abilities and quick thinking. Candidates might need to create a custom solution or apply a known algorithm to tackle a specific challenge.
Some of the examples are implementing sorting algorithms, constructing data structures, or navigating graphs.
System design questions
These particular questions assess a candidate’s abilities to design and implement scalable and maintainable software solutions. They require the candidate to design a system for a specific problem or may expect them to optimize an existing one.
Some of the examples are designing social media network APIs, algorithms for image processing, and components for a web application.
Language-specific questions
These questions evaluate a candidate’s expertise in specific programming languages. They can cover anything from basic language features to advanced concepts like inheritance, higher-order functions, or memory management.
Behavioral coding questions
These mix technical and behavioral skills. Candidates might need to explain how they’d tackle a real-world coding scenario, often involving teamwork.
For example, the interviewer may ask them, ‘How would they handle merging code from multiple developers with conflicting changes’?
Some of the other whiteboard programming interview questions can be of the following types:
- Debugging or code correction questions
- Puzzle or brain teaser questions
- Data structures questions
Furthermore, depending on the organization’s hiring requirements, interviewers may decide to build their own approach to these coding whiteboard interview questions.
How can organizations conduct whiteboard programming interviews?
Whiteboard programming interviews are a staple for tech companies across the globe. After all, they provide a unique way to evaluate a viable candidate’s problem-solving skills, communication, and coding proficiency.
However, these interviews can at time be stressful for the candidates and organizations to get right. Here’s how organizations can ensure they conduct whiteboard interviews fairly and effectively.
Start with clear objectives
The purpose of a coding whiteboard interview is not just to check if someone can write accurate code on a whiteboard. It’s to assess:
- Problem-solving approach
- Coding fundamentals
- Communication and collaboration skills
Define what you’re looking for in advance so your interview questions align with the role.
Select the right questions
Asking the right questions in a coding whiteboard interview is critical. They should be:
- Relevant to the role. A front-end developer shouldn’t have to answer for a back-end developer.
- Reasonable and not overly tricky. Pick questions that test the candidate’s skills on the job.
- Layered with a simple version of the problem. If candidates have time, they can build more on that.
Set the stage for success
Create an environment where candidates feel comfortable:
- Provide a clear problem statement: Ambiguity can be good for senior-level roles, but for entry-level candidates, clarity wins.
- Allow clarifying questions: Encourage candidates to ask questions. It shows their thought process and ability to collaborate.
- Offer tools: Use actual whiteboards, online collaborative platforms, or pen-and-paper, and let the candidates pick what suits them best.
Focus on the process, not perfection
It’s not just about the end result. Pay attention to:
- How they think: Are they methodical? Do they break the problem into parts?
- How they communicate: Do they explain their choices and ask for feedback?
- How they adapt: Do they handle hints well and improve their solution?
Remember, a messy solution with great reasoning is often more valuable than a perfect one without explanation.
Create a two-way interaction
The best interviews feel like conversations, not interrogations. Engage with the candidate during the process:
- Ask them why they made a particular decision.
- Offer subtle guidance if they get stuck.
- See how they handle feedback or alternative approaches.
This gives insight into their mindset and helps candidates feel more at ease.
Evaluate soft skills as well
Whiteboard interviews are a great opportunity to assess non-technical traits like:
- Composure under pressure: Do they stay calm or get flustered?
- Collaboration: Are they open to discussion and feedback?
- Curiosity: Do they ask thoughtful questions or suggest alternate solutions?
Provide feedback
Candidates appreciate constructive feedback. If possible, give them detailed insights into their performance and the kind of skills or tasks they could improve upon. This will reflect well not only on your organization but will also help you stand out as a thoughtful employer.
How can candidates prepare for whiteboard programming interviews?
Begin practicing with mock interviews
The best way to prepare for a whiteboard programming interview is to practice as much as possible. Candidates can do that by participating in mock interviews available online or take help from friends, colleagues, or mentors.
Mock interviews allow prospectives candidates to practice their problem-solving skills and get feedback on their performance.
Stay organized
Candidates must ensure that their code is organized and clean, uses clear variable names, and is well-structured. Using pseudo-code or drawing diagrams can help them stay organized during coding. They should also be mindful of their time and try to use the time allocated to reflect their skills and clarity of thought.
Communicate thought process
One key thing that interests interviewers is, how does a candidate approach and solve problems, work on the problem. They also want to know how do candidates work on the problems and communicate their thought process with the interviewer.
Candidates should be able to explain their approach and the reasoning behind it clearly. This will in turn help the interviewer understand their problem-solving skills and critical thinking ability.
Be mindful of the time
One of the challenges of whiteboard programming interviews is time management. Candidates must be mindful of it. They should not waste too much time on a single problem if they get stuck. They can do so by setting a timer, and aim to finish the interview within the stipulated duration.
Optimize for time and space complexity
After a candidate has a working solution, they should optimize it for time and space complexity. This means reducing the amount of time and memory required to solve the problem.
Interviewers are looking for efficient solutions that can scale well. As the candidate optimizes their solution, they should explain their thought process to the interviewer.
Write clean and readable code
When writing a code, candidates should ensure it is clean, organized, and easy to understand. They should also use appropriate variable names, comments, and formatting to make codes easy to understand. This will help the interviewer follow candidates’ thought processes and better understand their solutions.
Test own solutions
After a candidate has written a code, they must test it thoroughly. They should ensure it works for different test cases, including edge cases. If they find a bug, they should fix it and test again. This will help them catch mistakes and ensure their code works as expected.
Don’t give up
If candidates get stuck on a problem, they should not give up. Try thinking of solving problem from a different perspective or try a different approach. They should know that the interviewer is not expecting them to solve every problem perfectly. They are interested in knowing – about the candidates problem-solving skills and the ability to think out of the box.
Learn from mistakes
It’s crucial for candidates to take some time after an interview to consider their strengths and areas for improvement. They should ask the interviewer for their opinion. The premise is that people can grow from their mistakes and apply the criticism to boost their abilities.
Remain composed and self-assured
During their interviews, candidates need to know how to remain composed and self-assured. They ought to realize that the interviewer is not attempting to deceive or apprehend them. They want to observe how they tackle and resolve issues.
Therefore, candidates should not become alarmed if they make any mistakes; instead, they should stand back, assess the issue, and try again. The better, the more certain and composed they are the better.
Bottomline
If done properly, whiteboard coding interviews are a great way to assess potential talent. Creating an organized, equitable, and interesting process is crucial for organizations. Ultimately, the objective is not only to hire the finest applicant but also to make sure they represent your business favorably.
While whiteboard programming interviews might be difficult, candidates should know that they are also an opportunity to demonstrate their perseverance and logical reasoning.
Being methodical, maintaining composure, and approaching the issue as a discussion rather than an exam are the answers. Write clear, legible code, comprehend the issue, optimize for time and space complexity, and practice as often as you can. Lastly, candidates should not give up learning from their mistakes and stay confident.
Is your organization planning its next hire? Contact us to learn how InterviewVector can help you find the right talent for your team.