Explore

Discover courses, people, topics, and learning paths.

All courses

Official curriculum and practice interviews on this environment.

💻

Course

Software Engineering Interview Prep

Coding · System design · Behavioral

Live interview rooms with Agentic Owl — voice, whiteboard, and turn-by-turn practice.

🧩

Track

Coding interview

Software Engineering Interview Prep

Algorithms, data structures, and complexity — think aloud with Owl.

🏗️

Track

System architecture

Software Engineering Interview Prep

Production systems on a shared whiteboard — start with Social Media Feed.

d/dx

Course

BC Calculus I

Differential Calculus

Rates of change, limits, derivatives, and applications — inquiry-driven depth with Agentic Owl.

∫

Course

BC Calculus II

Integral Calculus

Riemann sums, the Fundamental Theorem, volumes, and differential equations — Socratic tutoring on th…

∞

Course

BC Calculus III

Infinite Series · Polar · Vectors

Infinite series, Taylor/Maclaurin, polar coordinates, and vector calculus — the advanced BC capstone…

🧩

Practice

Two Sum

Coding interview

Given an array of integers nums and an integer target, return the indices of the two numbers that ad…

🧩

Practice

Longest Substring Without Repeating Characters

Coding interview

Given a string s, find the length of the longest substring without repeating characters.

🧩

Practice

Merge Intervals

Coding interview

Given an array of intervals where intervals[i] = [starti, endi], merge all overlapping intervals and…

🧩

Practice

Binary Tree Level Order Traversal

Coding interview

Given the root of a binary tree, return the level order traversal of its nodes' values (from left to…

🧩

Practice

Number of Islands

Coding interview

Given an m x n 2D binary grid which represents a map of '1's (land) and '0's (water), return the num…

🏗️

Practice

Design a URL Shortener

System design

Design a URL shortener like Bitly. Users submit a long URL and receive a short code that redirects t…

🏗️

Practice

Design a Social Media Feed

System design

Design the news feed for a social platform like Instagram or X. Users create posts, follow others, a…

🏗️

Practice

Design a Chat System

System design

Design a chat/messaging system like WhatsApp: one-to-one messages, group chats, delivery/read receip…

🏗️

Practice

Design a Video Streaming Platform

System design

Design a video platform like YouTube: upload, store, transcode, and stream to millions of concurrent…

🏗️

Practice

Design a Ride-Sharing System

System design

Design a ride-sharing system like Uber: riders request trips, nearby drivers are matched, locations …

🏗️

Practice

Design Typeahead / Autocomplete

System design

Design a typeahead / autocomplete system. As the user types, return ranked prefix suggestions in und…

🏗️

Practice

Design a Rate Limiter

System design

Design a distributed rate limiter that enforces per-user or per-API quotas across many servers witho…

🏗️

Practice

Design File Sync / Dropbox

System design

Design a file sync service like Dropbox or Google Drive: upload, download, multi-device sync, and co…

🏗️

Practice

Design a Web Crawler

System design

Design a distributed web crawler that discovers URLs, fetches pages politely, stores content, and ke…

🏗️

Practice

Design a Notification System

System design

Design a multi-channel notification system: in-app, push, email, and SMS — with fan-out, preferences…