Dependency-Based FAANG Preparation: A 90-Day Technical Strategy

The 90 Day FAANG Prep Plan That Actually Works

Prakhar Srivastava outlines a 12-week FAANG preparation strategy that prioritizes topic dependency over surface-level difficulty. Failing to follow this order often results in candidates losing up to 50% of their study time to unplanned rework.

Why This Matters

Most preparation plans group topics by frequency or perceived difficulty, leading to a timeline collapse when candidates hit complex topics like Dynamic Programming without solid foundations in recursion or the call stack. This technical debt in learning creates unstable knowledge that fails under interview pressure, whereas a dependency-ordered approach leverages the spacing effect for durable recall.

Key Insights

• Dependency Sequencing: Data structure topics have hard prerequisites, such as Hash Tables unlocking prefix sums and Stacks being necessary for Tree traversal.
• Recursion Foundation: Dynamic Programming (DP) should be delayed until Week 11 to ensure candidates have internalized recursion and the call stack beforehand.
• The Spacing Effect: As summarized by Wikipedia, distributed practice across 12 weeks produces stronger recall than high-volume late-stage cramming.
• Timed Load-Bearing: Introducing timed practice at Week 6 bridges the gap between casual solving and the 20-minute constraints of technical interviews.
• Productive Struggle: Differentiating between spinning and productive struggle is critical; the latter involves naming specific gaps like O(n log n) divide steps.

Working Examples

A standard bottom-up Dynamic Programming solution for the Coin Change problem, requiring recursion and state-sharing fluency.

def coinChange(coins, amount):
    dp = [float('inf')] * (amount + 1)
    dp[0] = 0
    for a in range(1, amount + 1):
        for c in coins:
            if c <= a:
                dp[a] = min(dp[a], dp[a - c] + 1)
    return dp[amount] if dp[amount] != float('inf') else -1

Practical Applications

• Use Case: Transitioning from desk practice to mock interviews after Week 6 to build pressure tolerance. Pitfall: Skipping foundations to stay on schedule, which compounds gaps into later topics.
• Use Case: Using Month 1 to master Arrays and Hash Tables as prerequisites for Graph and Tree patterns. Pitfall: Treating DP as a Week 3 topic before internalizing the call stack, leading to memorization instead of derivation.

References:

• https://dev.to/codeintuition/the-90-day-faang-prep-plan-that-actually-works-stop-studying-in-the-wrong-order-4he7