In 2023, I bombed every technical interview I took. Zero offers from eight applications. I was solving LeetCode problems randomly, cramming system design the night before, and showing up to behavioral rounds hoping I could wing it.
In 2025, I got offers from three FAANG-level companies in the same month. My raw intelligence did not change. My system did.
Here is the exact prep system I used, broken down by interview type, with specific timelines and resources.
The Timeline: 8 Weeks
If you are currently employed and can dedicate 2 hours per day on weekdays plus 4 hours on weekends, 8 weeks is enough to prepare for any top tech company. Here is how I allocated the time:
| Week | Focus | Hours/Week |
|---|---|---|
| 1-2 | Data Structures & Patterns | 14 |
| 3-4 | Algorithms & Problem Solving | 14 |
| 5-6 | System Design | 14 |
| 7 | Behavioral & Company Research | 14 |
| 8 | Mock Interviews & Review | 14 |
Total: ~112 hours. That is roughly the same time investment as binge-watching three seasons of a TV show. The ROI is significantly better.
Phase 1: Data Structures and Patterns (Weeks 1-2)
Do not start by solving random problems. Start by learning the 14 core patterns that cover 90% of coding interview questions.
The 14 Patterns
- Two Pointers
- Sliding Window
- Fast and Slow Pointers
- Merge Intervals
- Cyclic Sort
- In-Place Reversal of Linked List
- Tree BFS
- Tree DFS
- Two Heaps
- Subsets
- Modified Binary Search
- Top K Elements
- K-Way Merge
- Dynamic Programming (Knapsack patterns)
For each pattern, solve 3-5 problems in this order:
- Read the pattern explanation
- Solve an Easy problem with the pattern
- Solve a Medium problem
- Try a Hard problem (it is OK to look at solutions here)
- Re-solve the Medium problem from memory the next day
The re-solve step is crucial. It moves the pattern from short-term to long-term memory.
Phase 2: Algorithms and Problem Solving (Weeks 3-4)
Now you have the patterns. Time to build speed and confidence.
The 75-Problem Core List
Instead of randomly browsing LeetCode, use a curated list. The "Blind 75" or "NeetCode 150" lists cover the most frequently asked problems across FAANG companies. I used NeetCode 150 and solved about 100 of them in two weeks.
The Problem-Solving Protocol
For each problem, follow this exact process:
- Read the problem. Do not code yet. (2 minutes)
- Identify the pattern. Which of the 14 patterns applies? (1 minute)
- Write pseudocode on paper. Not on the computer. Paper forces clarity. (5 minutes)
- Code the solution. (10 minutes)
- Test with edge cases. Empty input, single element, very large input. (3 minutes)
- If stuck after 20 minutes, look at the solution. Do not waste time being stuck. Learn the approach, then re-solve it tomorrow.
Track Everything
I kept a spreadsheet with columns for: Problem Name, Pattern, Difficulty, Solved (Y/N), Time Taken, Notes. This let me identify which patterns I was weak on and focus my review time.
Phase 3: System Design (Weeks 5-6)
System design interviews terrify most candidates. They feel open-ended and subjective. But there is a repeatable framework.
The 5-Step System Design Framework
Step 1: Clarify Requirements (3-5 minutes)
Ask questions. How many users? Read-heavy or write-heavy? What are the core features for MVP? What are the non-functional requirements (latency, availability, consistency)?
Step 2: High-Level Design (5-7 minutes)
Draw the major components: client, load balancer, application servers, database, cache, message queue. Keep it simple.
Step 3: Deep Dive (10-15 minutes)
Pick the most interesting or complex component and go deep. This is where you show expertise. Database schema, API design, caching strategy, or data partitioning.
Step 4: Address Bottlenecks (5 minutes)
Where will this system fail at scale? How would you handle it? This is where you discuss sharding, replication, CDNs, and rate limiting.
Step 5: Wrap Up (2 minutes)
Summarize your design and mention trade-offs you made.
The 15 System Designs to Study
These cover the vast majority of system design questions:
- URL Shortener (TinyURL)
- Twitter/X Feed
- Instagram/Photo Sharing
- Chat System (WhatsApp)
- Web Crawler
- Notification System
- Rate Limiter
- Search Autocomplete
- YouTube/Video Streaming
- Uber/Ride Sharing
- Dropbox/File Storage
- Ticketmaster/Event Booking
- News Feed Ranking
- Payment System
- Distributed Cache
Study two per day. For each, write out your own design before looking at solutions.
Phase 4: Behavioral Interviews (Week 7)
Most engineers neglect behavioral prep. This is a mistake. At senior levels, the behavioral round can be the deciding factor.
The STAR Method (But Better)
Everyone knows STAR: Situation, Task, Action, Result. But most people tell boring STAR stories. Here is how to make them compelling:
- Situation: Set it up in 2 sentences. No backstory novels.
- Task: What was your specific responsibility? Not the team's. Yours.
- Action: This should be 60% of your answer. Be specific about what YOU did.
- Result: Quantify it. "Reduced latency by 40%" beats "It worked well."
The 8 Stories You Need
Prepare 8 stories that you can adapt to any behavioral question:
- A time you led a technical decision
- A time you resolved a conflict with a teammate
- A time you dealt with ambiguity
- A time you failed and what you learned
- A time you went above and beyond
- A time you had to influence without authority
- A time you simplified something complex
- A time you had to make a tradeoff between speed and quality
Practice telling each story in under 2 minutes. Record yourself. It feels awkward, but it works.
Company Research
Spend 2-3 hours researching each company you are interviewing with:
- Read their engineering blog (last 10 posts)
- Understand their tech stack
- Know their recent product launches
- Have 3-5 thoughtful questions prepared for each interviewer
Phase 5: Mock Interviews (Week 8)
The single highest-ROI prep activity is mock interviews. Nothing else comes close.
Where to Find Mock Interview Partners
- Pramp — Free, peer-to-peer mock interviews
- Interviewing.io — Anonymous practice with real engineers
- Friends in tech — The best option if you have them
- AI tools — For solo practice when partners are not available
Do at least 6 mock interviews: 2 coding, 2 system design, 2 behavioral. After each one, write down what went well and what to improve.
The Tool I Wish I Had Earlier
One resource I found invaluable for structuring my prep was Interview Prep Tool. It helps you organize your preparation by role and company, generating targeted practice questions and helping you structure your STAR stories. I used it to make sure I was not over-indexing on coding while neglecting behavioral prep.
Day-Of Tactics
A few things that made a measurable difference:
- Sleep 8 hours. Not 6. Not 7. Eight. Your problem-solving ability drops 30% with poor sleep.
- Eat a real meal 2 hours before the interview. Not right before (food coma) and not nothing (low blood sugar).
- Arrive 10 minutes early for virtual interviews. Test your audio, video, and screen share.
- Think out loud. Interviewers cannot give you credit for what is happening silently in your head.
- Ask clarifying questions. It is not a sign of weakness. It is a sign of thoroughness.
The Uncomfortable Truth
Interviewing at top tech companies is a skill separate from engineering. You can be a brilliant engineer and bomb interviews. You can be an average engineer and ace them.
The system I described is not about becoming smarter. It is about deliberate, structured practice over a focused period. Anyone can do it.
If you want a structured way to organize your prep, check out Interview Prep Tool — it is free and helps you build a personalized study plan. But whether you use a tool or a spreadsheet, the key is consistency.
Eight weeks. Two hours a day. That is the price of a career-changing offer.
Start today.
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