The Complete Coding Interview Prep Timeline — 12 Weeks with AI
A week-by-week 12-week plan for coding interview prep — pattern practice, mocks, system design, behavioral — with an AI copilot embedded at each stage.
Twelve weeks is the sweet spot for FAANG-tier coding interview prep for a working engineer — enough time to build pattern fluency without letting the material go stale. Below is a week-by-week plan, plus how to weave an AI copilot into each stage so you learn instead of just grinding.
Ground rules
- ~10 hours/week. Two evenings and one weekend day. More if you can, but this is enough.
- Volume matters, but repetition matters more. Solving 200 unique problems is worth less than solving 100 unique problems twice.
- Time-box every problem at 30 minutes. If you're stuck, read the solution, understand it, redo it two days later.
- Say your approach out loud. Even alone. Interviews are graded on communication as much as code.
The 12 weeks
Week 1
Foundations
Goal: Reactivate arrays, hashing, two pointers.
Work
- 15 Easy Arrays + Hashing
- 10 Easy Two Pointers
- Watch 2 pattern videos
AI leverage
Use the AI to explain complexity trade-offs on every solution — you should be able to state O(N) vs O(N log N) without thinking.
Week 2
Sliding window + stack
Goal: Learn to spot windowed vs monotonic patterns.
Work
- 12 Sliding Window Medium
- 8 Stack Medium
- 1 Mock coding round
AI leverage
Ask the AI: "which of these problems could be solved with a monotonic stack?" — a great pattern-recognition drill.
Week 3
Binary search + trees
Goal: Rewrite recursion mentally.
Work
- 10 Binary Search Medium (including "answer space" ones)
- 20 Tree DFS / BFS Medium
AI leverage
Have the AI convert your recursive solution to iterative with an explicit stack, so you have both in your head.
Week 4
Linked list + heap
Goal: Understand pointer manipulation deeply.
Work
- 15 Linked List Medium
- 10 Heap / Top-K Medium
AI leverage
When you get stuck on a linked list corner case, ask the AI for a "dry run" — value at each pointer per iteration.
Week 5
Graphs
Goal: BFS, DFS, topological sort, Union-Find.
Work
- 20 Graph Medium
- 3 Hard graph problems
AI leverage
Ask the AI to draw a small example graph and trace your traversal — sniffs out off-by-one errors instantly.
Week 6
DP part 1
Goal: Get comfortable with 1D DP.
Work
- 15 1D DP Medium (coin change family)
- 1 Mock
AI leverage
Every DP problem: ask the AI "what is the state, what is the transition, what is the base case?" — until you can answer without asking.
Week 7
DP part 2
Goal: 2D DP + state machine DP.
Work
- 15 2D DP Medium (grid, string edit distance)
- 5 State machine DP (stock problems)
AI leverage
Have the AI generate a visual grid trace for at least one 2D DP per session.
Week 8
Backtracking + greedy
Goal: Pattern-match generate-all vs optimize.
Work
- 12 Backtracking Medium
- 10 Greedy Medium
- 1 Mock
AI leverage
The AI is a great "sanity check greedy" partner — ask it to construct a counterexample when you think a greedy solution works.
Week 9
System design intro
Goal: Learn the 4 diagrams.
Work
- Read the top 5 classic problems (Twitter, URL shortener, Uber, Chat, Feed)
- Do 2 mock system design rounds
AI leverage
Turn on System Design mode. Screenshot a problem, look at what the AI proposes, then re-draw it yourself so you internalize the structure.
Week 10
System design deep dive
Goal: Storage, messaging, scaling.
Work
- Read 10 more system design problems
- Do 2 more mock rounds
AI leverage
Ask "what would break at 100x scale?" on every design. Trains you for the follow-up questions.
Week 11
Behavioral prep
Goal: Build a 30-story bank.
Work
- Write 30 STAR-format stories
- Do 2 behavioral mocks
AI leverage
Toggle speaker mode. Have a friend ask you behavioral questions. The AI transcribes so you can review your delivery afterwards.
Week 12
Full mocks + tune
Goal: Simulate the real day.
Work
- 3 full mock loops (coding + system design + behavioral)
- Fix the 10 things you keep botching
AI leverage
Use the AI as a post-mortem partner. Paste your transcript, ask "what would a strong candidate have said differently?"
What to skip
- Obscure DP variants. If you can do coin change, LIS, edit distance, and grid DP, you're fine.
- Trie problems past week 5. Two examples is plenty.
- Bit manipulation beyond one hour. Rare in modern interviews outside embedded roles.
- Company-specific "list of 500 problems" lists past 200 problems. Diminishing returns.
How the AI copilot changes the calculus
With an AI in the loop, weeks 1-8 compress about 25%. You spend less time stuck on "I don't understand what this problem is asking" and more time on the actual algorithmic thinking. The catch is that if you let the AI think for you, you skip the reps and freeze up on interview day. Use these three rules to stay honest:
- State your hypothesis before you look at the AI's answer. This is the pattern-recognition rep you're actually training.
- Type every line of code yourself. No copy-paste. The muscle memory matters.
- Re-solve every problem two days later without the AI. If you can't, you didn't learn it.
Where Interview Helpers fits
The AI part of this workflow works with any tool. If you want the same experience during a real interview (stealth overlay, hotkey capture, system-design diagrams), that's what Interview Helpers is for. See the LeetCode workflow and system-design mode for how each week's practice translates directly into interview-day muscle memory.
Grab the Windows overlay for the trial — 10 free messages, 5 min of speaker mode, no credit card. Enough to run one full mock loop end-to-end.
Related reading
How to Solve a LeetCode Medium in Under 15 Minutes with GPT-5.6
A repeatable process for solving LeetCode Medium problems fast using an AI copilot — hypothesis, screenshot, verify, code, test, complexity — with concrete examples.
8 min read
How to Hide an App from Zoom, Google Meet, and Teams Screen Share (2026)
Exactly what Zoom, Google Meet, and Microsoft Teams can and cannot see when you share your screen — and how a stealth overlay app stays invisible.
7 min read
Why Multi-Model AI Beats Single-Model AI in Live Coding Interviews
GPT-5.6 Terra for reflex answers, Claude Sonnet 5 for nuanced reasoning, Opus 5 for the hardest problems — when to switch models mid-interview and why.
7 min read
Try Interview Helpers free
The AI interview copilot built for tech rounds. 10 free messages, no credit card.