Getting ready for coding interviews is no easy task Between studying algorithms, practicing on platforms like LeetCode, and brushing up on data structures, preparing can feel overwhelming But don’t worry – this ultimate guide has you covered with everything you need to know to totally rock your coding interviews.
Know What to Expect
Coding interviews typically involve a mix of behavioral and technical questions Here’s a quick overview of what to expect
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Behavioral Questions: These focus on your past experiences, how you’ve solved problems, and how you might approach hypothetical situations. Common behavioral questions include “Tell me about a challenging project you worked on and how you overcame obstacles” and “Describe a time you had a conflict with a coworker and how it was resolved.”
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Technical Questions Technical questions test your knowledge of computer science fundamentals like data structures and algorithms. You’ll likely get asked to write code to solve problems like reversing a linked list or finding duplicate elements in an array. Expect coding questions in languages like Java, Python C++ JavaScript, etc.
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System Design: Senior engineering roles may involve a system design component where you architect a complex system like a web crawler or Facebook’s newsfeed. This tests your ability to holistically solve open-ended problems.
Knowing the types of questions ahead of time allows you to target your studying appropriately.
Choose a Programming Language
Most companies let you code interview in any language, so choose one you’re extremely comfortable in. Stick to mainstream options like:
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Python: Succinct, optimized for developer productivity, great built-in data structures.
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Java: Statically typed, good for large systems programming, lots of open source libraries.
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C++: High performance systems and applications programming.
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JavaScript: Increasingly used on backend with Node.js, useful if interviewing for front-end roles.
Avoid lower-level options like C or Go that lack good standard libraries. The exception is if the role requires a specific language like iOS development using Swift.
Study Computer Science Basics
Coding interviews emphasize computer science fundamentals, so brush up on your knowledge of:
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Data structures: Arrays, linked lists, trees, graphs, hash tables, stacks, queues, heaps, etc. Know the tradeoffs, time complexities of operations, and how to implement them in code.
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Algorithms: Sorting, searching, breadth-first search, depth-first search, dynamic programming, string manipulation. Understand the algorithm approaches and implement code to solve problems.
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Object-oriented programming: Inheritance, polymorphism, abstraction, encapsulation. Be able to leverage OOP principles to write reusable, scalable code.
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Operating systems: Processes, threads, concurrency, locks, mutexes, semaphores, monitors. Understand how operating systems work under the hood.
Don’t just memorize concepts – write code to truly internalize data structures, algorithms, and OOP.
Practice on LeetCode
LeetCode provides over 1,800 algorithm questions and is the best way to practice coding interview questions. Aim to solve at least 100-200 questions across a wide range of topics and difficulty levels.
Get familiar with common patterns like two pointers, sliding windows, recursion, backtracking, and using hash maps. Focus on mastering techniques versus memorizing answers.
Do Mock Interviews
Mock interviews are critical to simulate the actual experience. Practice explaining your thought process clearly while coding on a shared editor. Get feedback on pacing, code quality, areas of improvement.
Resources like interviewing.io and Pramp match you with experienced engineers for mock interviews. Ask a friend to conduct practice interviews with you too.
Know What to Expect During the Interview
Now let’s walk through what actually happens during a coding interview:
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Clarify the Question: Restate the question back to the interviewer and ask clarifying questions. Validate requirements, edge cases, and assumptions.
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Explain Your Approach: Don’t immediately start coding! Walk through the high-level steps you’ll take to solve the problem. This validates your understanding.
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Write Pseudocode: Write out the precise steps in plain English before coding. This makes it easier to find flaws in logic.
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Write Actual Code: Only start coding once your interviewer greenlights the approach. Use clear variable names, good formatting, and explain what you’re doing.
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Test Your Code: Walk through example inputs to test your code. Look for edge cases. Fix any bugs that come up.
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Analyze Complexity: Explain the time and space complexity of your solution. Suggest ways to optimize if needed.
Following structured steps demonstrates your strong programming instincts.
Specialize by Job Role
While there is overlap, tailor studying based on the specific roles you’re targeting:
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Front-end: Focus on JavaScript, CSS, HTML, React, Angular. Study tree data structures, DOM manipulation, UI design principles.
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Back-end: Practice data structures and algorithms. Know system design and SQL queries. Understand caching, APIs, microservices, and how to scale systems.
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Full-stack: Study everything in front-end and back-end. Make sure you’re comfortable working across the entire stack.
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Data science: Review statistics, probability, linear algebra, and machine learning concepts. Know Python data analysis libraries like NumPy, Pandas, Matplotlib, and Scikit-learn.
Matching your skills to the role shows intentionality.
Rest Well Before the Interview
In the final week leading up to your interviews, shift focus from practicing to resting. Here are some tips:
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Sleep at least 8 hours the night before so you’re energized and focused.
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Avoid stressful activities or situations right before the interview.
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Eat foods that provide steady energy like oatmeal, nuts, or yogurt.
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Review your notes, but don’t try learning new concepts at the last minute.
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Visualize yourself succeeding and stay positive.
With rigorous preparation, you’ll walk into interviews ready to showcase your skills. Stay confident and calm – you got this!
How to NOT Fail a Technical Interview
FAQ
How many coding questions in 1 hour interview?
What to expect in a 1 hour coding interview?
What should I expect in a coding interview?
How does a coding interview proceed?
In a coding interview, you will be given a technical question by the interviewer. You will write the code in a real-time, collaborative editor or on a whiteboard, and have 30 to 45 minutes to solve the problem.
What kind of questions do coding interviewers ask?
While it’s impossible to anticipate every possible coding interview question, coding interviewers may ask computer science-based questions such as CS trivia, technical puzzles, or brainteasers. This is especially true for backend developer interviews, as companies may vary greatly in their questioning styles.
How long does a coding interview last?
A coding interview round typically lasts 30 – 45 minutes. During this time, you will be given a technical question and expected to write code to solve the problem within the given time frame.
How to get a good coding interview?
Fix any issues you find to make your code reliable. A systematic approach to problem-solving can unlock your coding interview potential. It shows the interviewer that you can break down complex problems and find effective solutions. In summary, mastering these techniques will not only help you in interviews but also in real-world coding challenges.
What to expect in a coding interview?
In a coding interview, you will face a broad question that tests your problem-solving skills. You might be asked to design a system, like “design YouTube”, and sketch out different components. Expect to communicate your thought process clearly and receive feedback from the interviewer. Coding interviews can vary widely. Here are some common types:
How much time do I need to prepare for coding interviews?
You will find the exact topics to study (with recommended links) and exact questions to practice (with practice links). How much time do you need to prepare for your coding interviews? Generally, 3 months (if you can dedicate 11 hours a week) is the recommended period of time for a more holistic preparation.