🎓 CS Prep Hub

C++ STL Guide

Deep dive into the Standard Template Library with detailed explanations of containers, iterators, and algorithms with practical examples.

Algorithm Patterns

Learn common algorithmic patterns including sorting, searching, dynamic programming, and graph algorithms with implementation details.

OOP Fundamentals

Master object-oriented programming concepts, the four pillars of OOP, design patterns, and SOLID principles for better software design.

Database Systems

Understand DBMS concepts, relational database design, normalization, SQL queries, indexing, and transaction management.

API Design

Learn to build scalable APIs from scratch. Includes REST principles, status codes, and a full Spotify-like system case study.

System Design

Master scalability, load balancing, caching strategies, and distributed systems. essential for senior engineering roles.

Backend Languages

Deep dive into Node.js/Express and Python/FastAPI. Learn setup, routing, and choose the right stack for your project.

Auth & Security

Secure your apps with JWT, OAuth 2.0, and HTTPS. Learn the critical difference between Authentication and Authorization.

DevOps Basics

Bridge the gap between code and ops. Dockerize your apps, automate with GitHub Actions, and explore deployment strategies.

Testing Strategies

Code without tests is legacy code. Master Unit Testing (Jest), Integration Testing, and proper TDD workflows.

Real-Time Apps

Build chat apps and live notifications using WebSockets and Socket.io. Move beyond standard HTTP requests.

GraphQL

The modern alternative to REST. Learn to fetch exactly the data you need with Apollo Server and strongly typed schemas.

Cloud Native

Go serverless with AWS Lambda, store data in DynamoDB, and manage infrastructure as code with Terraform.

Frontend Basics

For backend engineers. Understand the Critical Rendering Path, DOM manipulation, Flexbox/Grid, and React Hooks.

Behavioral Prep

Ace the soft skills interview using the STAR method. Learn to communicate technical challenges and conflict resolution effectively.

Sorting Algorithms

Master Merge Sort, Quick Sort, Heap Sort, and linear-time sorts. Includes custom comparator problems that appear constantly in interviews.

Searching Algorithms

Binary search and its variants — rotated arrays, first/last occurrence, answer-space search, and more.

Two-Pointer Technique

Replace O(n²) brute force with O(n) elegance. Covers pair sum, three sum, rain water, Dutch flag, and linked-list tricks.

Sliding Window

Fixed and variable-size windows for substring, subarray, and frequency problems — a must-have pattern for interviews.

String Algorithms

KMP, Z-algorithm, Rabin-Karp, anagram detection, palindromes, and every classic string problem you need.

Tree Algorithms

Binary tree traversals, BST operations, LCA, path problems, and segment trees — comprehensive coverage for tree-heavy interviews.

Graph Traversal — BFS & DFS

BFS for level-order and shortest paths in unweighted graphs; DFS for connected components, cycle detection, and flood fill.

Graph — Shortest Paths

Dijkstra, Bellman-Ford, Floyd-Warshall, and 0-1 BFS with worked problems for every weighted graph scenario.

Graph — MST & Topology

Kruskal and Prim for minimum spanning trees, Topological Sort (DFS & Kahn's), and Union-Find with path compression.

Greedy Algorithms

Activity selection, interval scheduling, Huffman coding, gas station, and every classic greedy pattern with proofs of correctness.

Backtracking

Subsets, permutations, N-Queens, Sudoku solver, and word search — the complete backtracking toolkit for hard interview problems.

Divide & Conquer

From the Master Theorem to binary search, merge sort, and closest-pair problems — understand the paradigm deeply.

Advanced Data Structures

Segment trees, Fenwick trees, Tries, Disjoint Set Union, and sparse tables — the structures that unlock hard problems.

DP — Foundations

Fibonacci, climbing stairs, coin change, and rod cutting. Build the core intuition for top-down vs bottom-up DP.

DP — Knapsack

0/1 Knapsack, unbounded knapsack, subset sum, partition equal subset — the family of problems that defines DP interviews.

DP — Matrix Paths

Unique paths, minimum path sum, dungeon game, and maximal square — grid DP in all its forms.

DP — String Problems

Edit distance, wildcard matching, regex matching, word break, and palindromic substrings — the hardest DP category.

DP — Subsequences

LCS, LIS, and their many variants. These patterns underlie a huge fraction of medium and hard DP interview questions.

Math & Number Theory

GCD, LCM, Sieve of Eratosthenes, modular arithmetic, fast exponentiation, and combinatorics for competitive programming.