Coding
Coding interviews are among the most common rounds in software engineering job interviews. Preparing for these interviews often takes substantial time, especially for those who haven’t studied data structures and algorithms in a while. However, coding interviews tend to play a less critical role in hiring decisions for senior positions, such as senior engineers or staff-level roles.
In my experience, many senior candidates over-prepare for coding interviews while spending too little time on other rounds. This is understandable, as coding interview preparation often feels more rewarding and predictable—solving 200 algorithm problems and passing all test cases on an online platform can boost confidence. In contrast, system design and behavioral interviews don’t offer the same tangible feedback, making them harder to gauge and improve.
With that said, let’s explore a minimal strategy for preparing for coding interviews efficiently.
Mindset
Focus on the Essentials: Don’t aim to master every algorithm and data structure. There are countless complex algorithms in computer science, and you’re likely to encounter a few difficult ones in interviews. But remember, your goal isn’t to become an ACM champion or solve every problem on LeetCode. Instead, aim to cover about 80% of the most common interview problems. The real objective is that when you do face a familiar type of problem, you can confidently find a solution within a reasonable timeframe.
Code, Don’t Just Think: Use platforms like LeetCode to practice by actually writing code, not just thinking through solutions or reviewing others’ answers. Writing the code yourself is crucial—it’s easy to fall into the trap of mentally “solving” problems without typing them out. If you don’t have time to code everything, at least become fluent in your chosen programming language and practice typing efficiently. It’s better to be highly skilled at writing solutions for 30% of common problems than to have reviewed 80% without true fluency. This is especially true for senior engineers.
Explore Multiple Approaches: For each problem, try to understand different solution methods and the reasoning behind them. Focus on time complexity, create your own test cases, and consider how you’d demonstrate software engineering best practices in an interview setting.
Preparation Steps
I recommend dividing your preparation into three parts:
Fundamentals (40% of your time): Spend around 40% of your preparation time strengthening your understanding of core data structures and algorithms. If you changed jobs recently (within the past year), you might only need to dedicate about 30% of your time to this. Resources like LeetCode can be helpful here, and a curated list such as NeetCode’s 75 or 150 problems can give you a solid foundation. During this stage, familiarize yourself with the containers, libraries, and language features you’ll likely use in interviews.
Targeted Practice (30% of your time): Dedicate 30% of your time to focusing on problems frequently asked by your target companies. LeetCode’s company-tag feature can help you filter questions by company, making it easier to identify common question types. Aim to practice around 100 problems (e.g., 50 high-frequency and 50 moderate-frequency questions) and become confident with at least 90% of them. Don’t get stuck on any single, extremely challenging problem. At this point, you should be comfortable with the most common data structures and algorithms and capable of producing a reasonably optimal solution even if it’s not the most efficient.
Company-Specific Review (Remaining 30% of your time): In the final stretch before your interview, revisit questions tagged for your target company on LeetCode. Optionally, check the discussion section on LeetCode for interview experiences shared by previous candidates. Use this with caution; while some experiences can provide insights, it’s best not to dwell too long here.
During the Interview
Be Honest: Don’t cheat, use AI tools, or attend the interview on someone else’s behalf. Interviewers can often detect dishonest behavior, even if they don’t have direct evidence, and they have the right to reject candidates who they suspect are cheating.
Prioritize Communication: Effective communication is key. Practice proactive communication during the interview—ask clarifying questions, confirm the problem requirements, and explain your approach before diving into the code. This shows the interviewer your thought process and ensures alignment.
Consider TDD Principles: Following Test-Driven Development (TDD) principles can be beneficial. Start by listing test cases before writing the solution, as this can help you clarify the problem requirements and spot potential edge cases.
Use Comments Strategically: Comments are a powerful communication tool. You don’t need to comment on every line, but use them to clarify complex sections of code. Well-placed comments make it easier for both you and your interviewer to follow along.