Table of Contents
- Introduction: Cracking the Coding Interview
- Step 1: Mastering Your Basics
- Step 2: Structuring Your LeetCode Practice
- Step 3: Solving Questions Like a Pro
- Leveraging Ninjafy AI for Your Interview Prep
- Conclusion: Trust the Process
Introduction: Cracking the Coding Interview
Coding interviews can be daunting, no matter how experienced you are. Whether you’re a fresh graduate or a senior software engineer, preparing for these interviews demands a structured and thoughtful approach. Having recently landed an offer from Facebook as a Senior Software Engineer, I want to share my tried-and-tested strategies for acing coding interviews, especially using LeetCode, the go-to platform for interview preparation.
This article isn’t just about solving questions but about learning patterns, optimizing your preparation time, and using tools like Ninjafy AI to get an edge. By the end, you’ll be armed with actionable advice to tackle interviews confidently.
Step 1: Mastering Your Basics
Before diving into practice, it’s crucial to revisit the fundamentals of data structures and algorithms. This step is often skipped by experienced engineers who feel they already use these concepts daily.
But here’s the truth: in real-world programming, we rely on high-level libraries and don’t necessarily think about the lower-level implementation details. However, interviewers expect you to know them inside out.
Key Areas to Cover:
| Data Structure | Operations to Know | Time Complexity to Memorize |
|---|---|---|
| Arrays | Access, Search | O(1) for access, O(n) for search |
| Linked Lists | Insertion, Deletion | O(1) for insertion, O(n) for search |
| Stacks/Queues | Push, Pop, Peek | O(1) |
| HashMaps | Insert, Lookup | O(1) (average case) |
| Trees | Traversals (DFS, BFS), Insertions | O(log n) for balanced trees |
Pro Tip: Watch a 10-minute overview video on data structures to refresh your knowledge. It’s a small investment of time that pays off during interviews.
Step 2: Structuring Your LeetCode Practice
LeetCode is an incredible resource, but with thousands of questions, it’s easy to feel overwhelmed. A clear strategy can help you get the most out of your practice time.
Difficulty Levels and Prioritization
LeetCode questions are categorized as Easy, Medium, and Hard. Here’s how to approach them:
- Start with Easy Questions: Build confidence and get comfortable with the platform.
- Focus on Medium Questions: Spend the majority of your time here. Medium-level questions strike the perfect balance between challenge and learnability.
- Sprinkle in Hard Questions: Prioritize only the popular hard questions that appear frequently in interviews. Many hard questions involve overly specific tricks that aren’t generalizable to other problems.
Topic-Wise Preparation Strategy
To ensure comprehensive preparation, cover questions across various topics. Here’s a suggested breakdown:
| Topic | Priority Level | Examples of Key Problems |
|---|---|---|
| Arrays & Strings | High | Sliding window, Two pointers |
| Dynamic Programming | High | Knapsack, Fibonacci sequence |
| Trees & Graphs | High | BFS, DFS, Dijkstra’s algorithm |
| Binary Search | Medium | Search in rotated arrays |
| Recursion | Medium | Backtracking problems |
| Design | Medium | LRU cache, System design basics |
| Heaps | Medium | Top K elements, Merge K sorted lists |
| Less Common Topics | Low | Tries, Union-Find, Linked Lists |
Pro Tip: Focus extra time on topics you struggle with. For instance, if recursion confuses you, dedicate a few days to recursive problems until it “clicks.”
Tracking Popular and High-Frequency Questions
If you’re targeting specific companies, LeetCode’s premium features like Company Tags and Sort by Frequency can be immensely helpful. These features let you focus on questions that users reported being asked at companies like Microsoft, Google, or Facebook.
If you’re on the free version of LeetCode, you can still:
- Search the company name on the Discuss Page to see real interview experiences.
- Use the likes/dislikes ratio of a question as an indicator of its quality and popularity.
Step 3: Solving Questions Like a Pro
Mastering LeetCode isn’t just about solving questions—it’s about learning patterns that can be applied to new problems. Here’s a step-by-step approach:
The Importance of Naive Solutions
Start by thinking of the naive approach to solve the problem. This is your baseline. Even if it’s inefficient, it gives you insight into:
- The bottlenecks causing high time/space complexity.
- The target performance of an optimal solution (e.g., if naive is O(n²), you might aim for O(n log n) or O(n)).
Testing with Examples and Edge Cases
Use small, manageable examples to test your ideas. Keep inputs simple (e.g., arrays with less than 5 elements). Look for patterns or rules that can be generalized.
Pro Tip: Don’t avoid edge cases. Actively think of inputs that could break your logic.
When to Seek Help and Learn from Solutions
If you’ve spent 30 minutes on a question and feel stuck, stop and:
- Read the solution or watch a solution video.
- Implement the solution yourself. Writing the code helps you understand it deeply.
- Ask yourself: “What concept or technique did I miss?” Make a note of it for future reference.
Leveraging Ninjafy AI for Your Interview Prep
During my preparation, I incorporated Ninjafy AI, an interview copilot that transformed my process. Here’s how it can help you:
- Mock Interviews: Ninjafy AI offers realistic mock interviews tailored to your resume and job position. Practicing with it felt like gaining months of experience in just a few weeks.
- Industry-Specific Assistance: With its Industry Brain, Ninjafy AI provided insights specific to my field (Software Engineering), ensuring I was prepared for situational and behavioral questions.
- Discreet AI Support: Its InvisibleEyetrack™ technology ensured I could confidently maintain eye contact during live interviews while receiving AI-generated suggestions in real time.
Fun Fact: Ninjafy AI has supported over 2.2 million interviews and helped secure 441,000+ offers globally.
If you’re looking for a fully undetectable assistant to boost your preparation, I highly recommend giving Ninjafy AI a shot.
Conclusion: Trust the Process
Every software engineer, no matter how skilled, finds coding interviews challenging. The key is to approach preparation systematically:
- Revisit your basics.
- Structure your practice on platforms like LeetCode.
- Learn from every question—whether you solve it or not.
And remember, tools like Ninjafy AI can give you an edge, but success ultimately comes down to persistence and consistent effort. You’ve got this!
