Problem-Solving Framework
When given a coding problem: clarify the problem (edge cases, input format, expected output), think through examples (small examples you can trace by hand), choose a data structure or algorithm pattern, code the solution while explaining your reasoning, test with the examples you thought through, and analyze time and space complexity. Narrating this process aloud is as important as the code itself - interviewers cannot see your thinking unless you share it.
Core Algorithm Patterns
Two pointers: used for sorted arrays, palindromes, pair-sum problems. Sliding window: for subarrays with constraints. BFS: shortest path, level-order traversal. DFS: tree traversal, path finding, backtracking. Binary search: any sorted structure where you need to find a value or boundary. Dynamic programming: optimization problems with overlapping subproblems. Learning to recognize which pattern applies to a problem is the core skill in coding interviews.
Practice Strategy
Practice on a whiteboard or in a plain text editor, not an IDE - coding interviews do not provide autocomplete or debugging tools. Solve problems timed (25-35 minutes for medium difficulty). After each problem, review the optimal solution even if you solved it correctly - there is often a cleaner or more efficient approach. Do mock interviews with another person at least weekly; coding while explaining aloud is a different skill than coding alone.
Top Resources
Neetcode.io provides categorized LeetCode problems with video explanations organized by pattern - widely considered the best free resource for structured coding interview preparation. Grind 75 (by the creator of Blind 75) is a customizable problem list. For system design (required at senior levels), Alex Xu's System Design Interview books are the standard reference. Pramp and Interviewing.io provide free peer mock interviews.
All Guides
LeetCode Study Plan: From Beginner to Ready
A structured 12-week LeetCode study plan covering 14 core algorithm patterns. Go from beginner to interview-ready for Google, Amazon, and Meta.
Time and Space Complexity for Interviews
Master time and space complexity analysis for coding interviews, with Big O fundamentals, optimization patterns, and clear communication techniques.
Recursion and Backtracking Interview Patterns
Master recursion and backtracking for coding interviews with problem patterns, templates, complexity analysis, and debugging techniques for permutations, combinations, and constraint problems.
How to Use Mock Interviews Effectively
Learn how to run, schedule, and debrief mock coding interviews to maximize learning and build the simultaneous coding and communication skills real interviews require.
How to Study for Coding Interviews in 8 Weeks
Complete 8-week coding interview study plan with week-by-week topics, daily practice structure, progress metrics, and error journaling strategy.
How to Approach Coding Problems Under Pressure
Master the five-phase coding interview process to solve problems systematically under pressure, with time management strategies and communication patterns.
Graph Algorithms Interview Prep
Prepare for graph algorithm coding interview questions with BFS, DFS, Dijkstra, Union-Find, and topological sort implementations and problem patterns.
Dynamic Programming Interview Guide
Dynamic programming interview guide: Master dynamic programming for coding interviews with a systematic framework, core DP patterns, optimization techniques.
Data Structures Interview Prep Guide
Master the data structures that appear most in coding interviews, with time complexity analysis, implementation notes, and problem pattern guides.
Binary Search Interview Patterns
Master binary search patterns for coding interviews, including classic search, rotated arrays, boundary conditions, and binary search on the answer.
Frequently Asked Questions
How long should I prepare for coding interviews?
For roles at mid-tier companies, 4-8 weeks of consistent daily practice (1-2 hours) is typically sufficient. For top-tier companies (Google, Meta, Amazon, Microsoft, Apple), plan 3-6 months of preparation including multiple weekly mock interviews. The goal is not to see as many problems as possible but to deeply understand the patterns underlying different problem types.
How many LeetCode problems do I need to solve to pass coding interviews?
Quality over quantity. Deeply understanding 75-150 high-quality problems across core patterns (two pointers, sliding window, BFS/DFS, dynamic programming, binary search, heap, graph algorithms) is more effective than rushing through 500 problems without internalizing patterns. Neetcode 150 and Blind 75 are widely recommended curated lists that cover the most frequently appearing patterns.
What data structures and algorithms should I focus on?
Arrays and strings (two pointers, sliding window), linked lists (fast/slow pointers, reversal), trees and graphs (BFS, DFS, recursion), hash maps and sets, stacks and queues, heaps and priority queues, binary search, and dynamic programming. Start with arrays and trees - they appear in approximately 60% of coding interview questions. Add graphs and DP after mastering the simpler structures.
Should I always find the optimal solution in a coding interview?
Not at the cost of finding a working solution. Start with a brute force approach, explain it, analyze its complexity, then work toward optimization. Interviewers care about your problem-solving process and communication more than finding the cleverest solution immediately. A correct O(n^2) solution that you can explain clearly and optimize toward O(n log n) is better than silence while searching for the optimal answer.
What does this Coding Interview Preparation section cover?
Coding interview preparation: Coding interviews test algorithmic thinking, data structure knowledge, and problem-solving communication under pressure. Structured preparation over weeks or months - not cramming - is the key to performing consistently well.