How to Prepare for a FAANG Coding Interview in 30 Days

Most candidates approach FAANG interview prep the wrong way. They open a problem list, jump between random topics, and measure progress by volume. That feels productive, but it misses what interviewers actually see. A strong performance is not just correct code. It is clear reasoning, good tradeoff discussion, disciplined testing, and the ability to recover when the first idea is not perfect.

If you are asking how to prepare FAANG interview rounds in a short window, think like an athlete in a four week training block. You need deliberate repetition, realistic mock interviews, and enough recovery that you do not fry yourself two days before the real thing. This coding interview 30 days plan is built around that.

What FAANG Interviewers Actually Look For

FAANG interviewers usually care about five things more than candidates realize:

1. How you frame the problem before coding.
2. Whether your fundamentals are strong enough to recognize common patterns quickly.
3. How clearly you communicate when you are under pressure.
4. Whether you test edge cases and debug with discipline.
5. How well you respond to hints or steering from the interviewer.

This is exactly why solo grinding is often not enough. Many candidates can solve a medium on their own, then underperform live because they rush into code, skip clarification, or go silent when stuck. If that sounds familiar, read why you keep failing live coding interviews before your next practice block. It explains the difference between offline success and real interview execution.

A Realistic 30-Day Study Plan

This plan assumes roughly two focused hours on weekdays and three to four on weekends. If you have extra time, use it for review and mocks, not endless new questions.

Days 1-3: Baseline and setup

• Solve three timed medium problems from arrays, strings, and hash maps.
• Track exactly where you lose time: understanding, approach selection, coding, or debugging.
• Start a study sheet for patterns, syntax mistakes, and behavioral stories.

Days 4-7: Core patterns first

• Practice two problems per day on sliding window, two pointers, arrays, strings, and hash maps.
• After each question, write down the pattern instead of only saving the answer.
• Spend 15 minutes daily explaining one solution out loud.

Days 8-10: Trees and recursion

• Cover DFS, BFS, tree traversal, and clean recursion templates.
• Focus on describing base cases and state clearly.
• Redo one earlier problem from memory to build fluency.

Days 11-14: Graphs and backtracking

• Practice traversal, visited-state management, and backtracking structure.
• Time yourself more aggressively now.
• End Day 14 with your first mock interview or full interview simulation.

Days 15-17: Heaps, intervals, and greedy

• Learn when sorting first helps, when a heap is the right tool, and when greedy logic is valid.
• Review the mistakes from your first mock in detail.
• Lock in a repeatable verbal structure: clarify, propose, discuss complexity, code, test.

Days 18-20: Dynamic programming basics

• Focus on state definition and transitions, not the hardest DP problems you can find.
• Build comfort with simple 1D and grid-based patterns.
• If a problem is too advanced, learn the pattern and move on instead of forcing it.

Days 21-23: Behavioral and company-specific prep

• Prepare concise stories for failure, conflict, ownership, ambiguity, and impact.
• Map your experience to the role and company values.
• If you have a system design round, cover one lightweight design topic per day.

Days 24-27: Interview simulation week

• Do at least two realistic mock interviews with another person.
• Keep the pressure real: camera on, timer running, no notes, no pauses.
• Spend more time reviewing each mock than taking it.

Days 28-29: Targeted cleanup

• Revisit the patterns that still feel shaky.
• Redo a representative set of problems from memory.
• Polish behavioral answers until they sound natural instead of memorized.

Day 30: Taper instead of cramming

• Do one light review session only.
• Confirm interview logistics and skim your notes.
• Stop early and protect your sleep.

Why Mock Interviews Matter

Mock interviews matter because they expose the invisible part of your performance. You might think your issue is algorithms when the real problem is that you code too early, freeze after a small bug, or fail to keep the interviewer aligned with your thinking.

That is why serious FAANG interview prep should include at least two high-quality mocks before the real loop. One strong mock can reveal whether your bottleneck is pacing, communication, nerves, or problem-solving structure. That is usually more valuable than doing five more random questions alone.

If you are rebuilding after a recent miss, read how to prepare for your next coding interview after a rejection. The recovery process is different from first-time prep, and getting that part right saves time.

How to Use This Month Well

Three rules keep this 30-day plan effective:

1. Prioritize pattern recognition over problem count.
2. Review every miss until you can explain it cleanly.
3. Practice like the interview is collaborative, not like a silent exam.

That is the practical answer to how to prepare FAANG interview rounds in a month. You do not need perfect coverage. You need enough technical range, enough structure, and enough live reps that an interviewer can trust how you think.