DSA Roadmap 2026: Master Data Structures and Algorithms for FAANG

Why DSA Still Matters in 2026

Despite debates about whether DSA interviews reflect real work, the reality is that top companies — Google, Meta, Amazon, Microsoft — all use DSA-based interviews. Mastering DSA is the entry ticket.

The Learning Order That Works

Weeks 1-2: Arrays and Strings — two pointers, sliding window, prefix sums. 30% of interview problems.

Weeks 3-4: Linked Lists — reverse, detect cycle, find middle, merge sorted.

Weeks 5-6: Stacks and Queues — monotonic stack, BFS using queue.

Weeks 7-8: Binary Search — not just find element. Binary search on answer is one of the most powerful patterns.

Weeks 9-10: Trees — BST, DFS, BFS. Most tree questions are DFS variations.

Weeks 11-12: Graphs — DFS, BFS, topological sort, union-find.

Weeks 13-16: Dynamic Programming — the hardest topic. 1D DP first, then 2D DP, then string DP.

Essential Patterns

# Two Pointers
def two_sum_sorted(arr, target):
    left, right = 0, len(arr) - 1
    while left < right:
        s = arr[left] + arr[right]
        if s == target: return [left, right]
        elif s < target: left += 1
        else: right -= 1

# Sliding Window
def max_sum_subarray(arr, k):
    window_sum = sum(arr[:k])
    max_sum = window_sum
    for i in range(k, len(arr)):
        window_sum += arr[i] - arr[i-k]
        max_sum = max(max_sum, window_sum)
    return max_sum

# Binary Search
def binary_search(arr, target):
    left, right = 0, len(arr) - 1
    while left <= right:
        mid = (left + right) // 2
        if arr[mid] == target: return mid
        elif arr[mid] < target: left = mid + 1
        else: right = mid - 1
    return -1

Practice Plan

Months 1-2: LeetCode Easy — 70-80 problems. Speed is the goal.

Months 3-4: LeetCode Medium — 100-150 problems. This is where most interviews live.

Months 5-6: Company-specific problems + mock interviews.

Consistency beats intensity: 1-2 problems daily beats 500 problems in a 2-month sprint.

Mock Interviews Are Non-Negotiable

Solving problems alone is different from solving them out loud with someone watching. Use Pramp (free peer mock interviews) or interviewing.io. The first few mock interviews are humbling — you realise how different talking through code is from typing it silently. See the DSA Academy for structured practice.