How to Prepare for a Coding Interview: Complete 2025 Guide
The complete roadmap to prepare for coding interviews at any company, from startups to FAANG. Includes study plans, topic prioritization, and practice strategies.
Preparing for a coding interview can feel overwhelming. This guide breaks down exactly what you need to study, how to practice effectively, and what to expect on interview day.
Step 1: Assess Your Timeline
Recommended preparation time:
- 1-2 weeks: Refresh fundamentals, focus on most common patterns
- 1-2 months: Comprehensive preparation for most companies
- 3-6 months: FAANG-level preparation with deep expertise
Step 2: Master the Fundamentals
Essential data structures (in order of importance):
- Arrays and Strings - Foundation of most problems
- Hash Maps/Sets - O(1) lookups, counting, duplicates
- Linked Lists - Pointer manipulation practice
- Stacks and Queues - Parsing, BFS, monotonic patterns
- Trees and Graphs - DFS, BFS, traversals
- Heaps - Top K problems, scheduling
Essential algorithms:
- Two Pointers - Array/string problems
- Sliding Window - Subarray/substring problems
- Binary Search - Sorted arrays, search space reduction
- BFS/DFS - Graph traversal, tree problems
- Dynamic Programming - Optimization problems
- Backtracking - Permutations, combinations
Step 3: Practice Strategy
Quality over quantity. Focus on understanding patterns rather than memorizing solutions. For each problem: spend 20-30 minutes attempting, study the solution if stuck, implement from scratch, and review after 1 week.
Recommended practice approach:
- Start with easy problems to build confidence
- Progress to medium problems (bulk of interview questions)
- Hard problems only after mastering medium
- Practice explaining your thought process out loud
- Time yourself to simulate interview pressure
Step 4: Mock Interviews
Solving problems alone is not enough. You need to practice communicating your thought process, handling hints, and managing time pressure. Do at least 5-10 mock interviews before your real interviews.
Our AI Mock Interview simulates real interview conditions. Practice explaining your approach, receive hints when stuck, and get feedback on your problem-solving communication.
Practice with AI Mock Interviews
Put your knowledge to the test with our AI interviewer.