Core Curriculum
Topic-by-topic problem sets covering the full data-structures & algorithms canon.
Sorting, Searching & Hash Tables — Basics
Merge sort, quick sort, heap sort, binary search, hash tables, edit distance, and iterator patterns — the essentials.
Core CurriculumSorting, Searching & Hash Tables — Advanced
Advanced variations on sorting, searching and hashing: harder problems built on the basic toolkit.
Core CurriculumTrees & Graphs — Basics
Binary trees, BSTs, traversals, and graph fundamentals with BFS/DFS.
Core CurriculumTrees & Graphs — Advanced
Harder tree and graph challenges: balancing, path problems, and non-trivial graph algorithms.
Core CurriculumBig-O, Linked Lists, Stacks, Queues & Bitwise
Complexity analysis, linked-list manipulation, stack/queue problems, and bit-manipulation techniques.
Core CurriculumMatrices, Arrays & Unit Testing
2-D matrix challenges (rotation, spiral, zeroing), array problems, and unit-testing patterns for interviews.
Core CurriculumStrings & Tries — Basics
String manipulation, pattern problems, and trie fundamentals.
Core CurriculumStrings & Tries — Advanced
Advanced string algorithms and trie-based challenges.
Core CurriculumRecursion, Memoization & NP-Completeness
Recursive problem-solving, memoization and dynamic programming, plus NP-complete classics.
Company Question Sets
Real interview question collections from FAANG-style loops, worked end to end.
Apple Interview Questions
A worked set of Apple-style interview challenges with solutions and notes.
Company Question SetsMeta (Facebook) Interview Questions
Meta/Facebook interview questions — LeetCode-numbered problems and the recruitment-portal challenge set.
Company Question SetsGoogle Interview Questions
Google interview questions with detailed solutions.
Company Question SetsAmazon Interview Questions
Amazon interview questions with detailed solutions.
Company Question SetsMock Interviews: Four Company Simulations
Full phone-screen + on-site simulations for a search-engine giant, an e-commerce company, a social network, and a ride-share start-up.
Special Topics & Data Wrangling
LeetCode special topics plus pandas/SQL drills for data-heavy roles.
LeetCode Special Topics
Special-topic LeetCode problems: patterns that keep reappearing in senior-engineer screens.
Special Topics & Data WranglingMiscellaneous Challenges
Assorted challenges worth knowing if time permits, plus a data-management coding question.
Special Topics & Data WranglingPandas vs. SQL: Data Wrangling Drills
Merge/join, group-by, missing values and outliers — the same operations side-by-side in pandas and SQL.
Special Topics & Data WranglingPandas Cheatsheet
A rapid-fire pandas reference: indexing, reshaping, aggregation, and idioms for data-heavy interviews.
Fundamentals: Deep Dives & Classic Problems
From-scratch implementations, classic problem sets, and brain teasers.
Algorithm Analysis & Big-O
Why we analyze algorithms, formal Big-O notation, worked examples, and Big-O costs of Python's built-in data structures.
Fundamentals: Deep Dives & Classic ProblemsSorting Algorithms — Deep Dives
Each classic sorting algorithm explained and implemented from scratch: bubble, selection, insertion, shell, merge, and quick sort.
Fundamentals: Deep Dives & Classic ProblemsSearching & Hash Tables — Deep Dives
Sequential search, binary search, and building a hash table from first principles.
Fundamentals: Deep Dives & Classic ProblemsArray Sequence Problems
Dynamic arrays under the hood, plus the classic array interview set: anagram check, pair sum, missing element, largest continuous sum, sentence reversal, string compression, and unique characters.
Fundamentals: Deep Dives & Classic ProblemsStacks, Queues & Deques
Concept overviews, from-scratch implementations, and the interview classics: balanced parentheses and a queue built from two stacks.
Fundamentals: Deep Dives & Classic ProblemsLinked Lists
Singly and doubly linked lists from scratch, plus cycle detection, reversal, and Nth-to-last-node interview problems.
Fundamentals: Deep Dives & Classic ProblemsRecursion & Memoization Problems
Recursion from first principles, memoization, homework problems, and the classic four: reverse a string, string permutations, Fibonacci three ways, and coin change.
Fundamentals: Deep Dives & Classic ProblemsTrees: Implementations & Problems
Tree representations, binary heaps, binary search trees, and tree interview problems: BST check, level-order print, and trimming a BST.
Fundamentals: Deep Dives & Classic ProblemsGraphs: Implementations & Problems
Graph representations (adjacency list), BFS and DFS implementations, word-ladder and knight's-tour examples, and graph interview questions.
Fundamentals: Deep Dives & Classic ProblemsLeetCode Classic Problems
Seventeen numbered LeetCode classics — two sum, add two numbers, longest palindromic substring, edit distance, word break, and more — each with multiple solution approaches.
Fundamentals: Deep Dives & Classic ProblemsInterview Riddles & Brain Teasers
The classic logic riddles: bridge crossing, coins and a scale, egg drop, hallway lockers, jugs of water, light switches, and burning ropes.