A complete, step-by-step data structures and algorithms tutorial series. Master the core concepts that appear in coding interviews at Google, Meta, Amazon, and every top tech company. Every article includes working code in Kotlin, Python, and Go.

Free. No paywall. From arrays to dynamic programming.


Part 1: Data Structures

#TutorialWhat You Will Learn
1Arrays and Strings (Coming Soon)Arrays, strings, two-pointer technique, palindromes, anagrams
2Linked Lists (Coming Soon)Singly, doubly, circular lists, reversal, cycle detection
3Stacks and Queues (Coming Soon)LIFO, FIFO, monotonic stack, valid parentheses
4Hash Maps and Sets (Coming Soon)Hashing, O(1) lookup, frequency counting, two sum
5Trees — Binary Trees and BST (Coming Soon)Traversals, BST operations, validate BST
6Heaps and Priority Queues (Coming Soon)Min-heap, max-heap, heapify, top K pattern, priority queues
7Graphs — Representation, BFS, and DFS (Coming Soon)Adjacency list, BFS, DFS, cycle detection, topological sort
8Tries (Prefix Trees) (Coming Soon)Insert, search, startsWith, autocomplete, word search
9Union-Find (Disjoint Sets) (Coming Soon)Path compression, union by rank, connected components
10When to Use Which Data Structure (Coming Soon)Decision framework, complexity cheat sheet, interview strategy

Part 2: Algorithms

#TutorialWhat You Will Learn
11Big O Notation (Coming Soon)Time and space complexity, how to calculate Big O, common complexities
12Sorting Algorithms (Coming Soon)Bubble sort, merge sort, quick sort, comparison table, when to use which
13Binary Search (Coming Soon)Templates, search on answer, rotated arrays, 2D matrix search
14Two Pointers and Sliding Window (Coming Soon)Converging pointers, fast/slow, fixed and variable sliding windows
15Recursion and Backtracking (Coming Soon)Call stack, backtracking template, subsets, permutations, N-Queens
16Dynamic Programming (Coming Soon)Memoization, tabulation, 1D and 2D DP, coin change, LCS
17Greedy Algorithms (Coming Soon)Greedy vs DP, interval scheduling, jump game, task scheduler
18BFS and DFS Deep Dive (Coming Soon)Dijkstra, multi-source BFS, grid problems, shortest path patterns

Part 3: Interview Patterns

#TutorialWhat You Will Learn
19Top 10 LeetCode Patterns (Coming Soon)Pattern recognition, decision flowchart, 10 core interview patterns
20String Manipulation Patterns (Coming Soon)Palindromes, anagrams, sliding window on strings, KMP algorithm
21Tree and Graph Patterns (Coming Soon)DFS/BFS variants, path problems, LCA, topological sort patterns
22Dynamic Programming Patterns (Coming Soon)Knapsack, string DP, grid DP, interval DP, state machine DP
23System Design vs DSA (Coming Soon)Interview pipeline, study allocation by level, how DSA powers system design
24How to Practice DSA Effectively (Coming Soon)Study plan, spaced repetition, Blind 75, NeetCode 150, mock interviews
25DSA Cheat Sheet (Coming Soon)All data structures, algorithms, patterns, and code templates in one page

Who is This For?

  • Developers preparing for coding interviews at FAANG and top tech companies
  • Self-taught programmers who want a solid computer science foundation
  • Career switchers entering software development
  • Anyone who wants to understand data structures and algorithms from scratch

Prerequisites

  • Basic programming knowledge in at least one language
  • Familiarity with variables, loops, functions, and classes
  • No computer science degree required

Why Kotlin, Python, and Go?

Every article shows solutions in three languages:

  • Python — the most popular interview language (60%+ of candidates use it)
  • Kotlin — great for Android developers preparing for interviews
  • Go — growing fast for backend and systems roles