So, you’re looking for a coder. But how do you tell who’s the real deal and who’s just scraping by with Stack Overflow? If you want to avoid hiring someone who’s gonna ship buggy code and then disappear when the errors hit production, you’ve got to ask the right coding interview questions.
You don’t need a question bank filled with impossible algorithm puzzles. Instead, go for questions that reveal how a candidate thinks, solves problems, and—most importantly—writes clean code that doesn’t blow up.
We’ll break down the best coding interview questions you should be asking, pulled straight from real developers.
The best coders don’t just know how to write code—they know how to troubleshoot, optimize, and communicate their solutions. When you're hiring, you need to find out if your candidate can:
The goal is to weed out the “copy-paste” coders and find the ones who can really think through a problem.
You’re here for more questions, right? Here’s an expanded list of coding interview questions inspired by devs from Reddit and beyond. These will help you uncover their skills, decision-making, and coding style.
This is a big one. It’s not just about making things work, it’s about making sure the code is easy to read, easy to update, and doesn’t require a whole team to fix later. You want someone who’s serious about structure, readability, and long-term maintainability.
Debugging is part of the job. If they can’t explain a gnarly bug they fixed and how they went about it, they might not have enough experience in troubleshooting. Great answers will walk you through their debugging process—step by step.
This one tests their creativity and willingness to improve. It also shows how they think about refactoring, scaling, or optimizing their work. Are they someone who’s always looking to make things better, or are they satisfied with “good enough”?
Technology moves fast, and you want someone who can keep up. Look for answers that highlight a candidate’s ability to adapt and learn quickly—whether it’s through personal projects, bootcamps, or hands-on experience at work.
Not every dev loves writing tests (we get it), but the best ones know how important they are. This question will help you see if they think about test coverage, edge cases, and making sure their code is solid before it gets shipped.
This is where you hear about a real battle they’ve fought (and hopefully won). You want to see how they approach difficult challenges—do they stay calm, break things down logically, or do they get overwhelmed?
This is more of a live coding exercise, but you’ll learn a lot from watching how they clean up a mess. Do they prioritize readability? Do they spot inefficiencies? Can they explain why they’re making changes?
Legacy code can be a nightmare, but it’s a reality for many devs. The best candidates will have strategies for navigating outdated systems and making improvements without breaking everything.
Algorithm questions don’t have to be about showing off. This question helps you see how they’ve used algorithms in real-world situations to improve performance or solve specific problems.
This question isn’t just about whether they know how to use Git. It’s about how they manage their workflow, how they handle branches, and whether they follow best practices for commits and pull requests.
We’ve all been there—something’s broken in production, and the clock is ticking. This question helps you understand how they handle high-pressure situations and whether they have a clear process for identifying and fixing issues without making things worse.
You’re looking for someone who knows when to optimize and when to ship. Writing perfect code is great, but not if it delays the project. The best coders can find a balance between clean, efficient code and meeting deadlines.
It’s not all about coding—teamwork matters too. You want to know how they handle conflict, especially when it comes to disagreeing on technical approaches or project direction.
This might sound like a simple question, but it can tell you a lot about their preferences and depth of knowledge. If they’re passionate about a language, you’ll get insight into their experience with it and why it suits their style of problem-solving.
Now that you’ve got a solid list of questions, what makes a good answer? Here’s what you should be looking for in their responses:
Not every candidate is going to crush these questions. Here are a few red flags that might indicate they’re not ready for the role:
At the end of the day, coding interviews are about more than just finding someone who knows the syntax of a language. You need someone who can think critically, solve problems, and collaborate with your team without causing a headache.
These coding interview questions help you dig deeper and get a real sense of who can handle the job, not just who can talk their way through an interview.
And remember, it’s not just about how well they code—it’s about how well they work with the rest of your team, how they handle pressure, and how they approach challenges. So don’t be afraid to push for those details.
The 5 C's of interviewing include Competency, Character, Communication Skills, Culture Fit, and Career Direction. Competency involves having the necessary technical skills for the task, often assessed through technical evaluations during the interview.
To conduct an effective interview, start by making the applicant comfortable, such as by establishing rapport with a shared topic before diving into more challenging questions. Utilize open-ended questions to encourage detailed responses, listen more than you speak, take notes diligently, and be mindful of legal boundaries in questioning.
When giving an interview, it's advisable to arrive early, prepare a brief summary of your experience relevant to the position, listen attentively to each question, maintain a positive demeanor while avoiding negative remarks about previous employers, and be conscious of your body language and tone.
A good interview should begin with a friendly opening to make the candidate feel at ease, followed by proper introductions. Set clear expectations for the interview, treat it as a conversational exchange to gather essential information, and share your leadership philosophies. Finally, allow the candidate to ask their own questions.
