Programming
C, C++, Java, Python & more
Web Development
HTML, CSS, JS, React, Next.js
Data Science
NumPy, Pandas, SQL, Big Data
AI & Machine Learning
ML, Deep Learning, Gen AI
System Design
OS, DBMS, Cloud Architecture
DSA
Arrays, Trees, Graphs & DP
Git & DevOps
Version control & CI/CD basics
IoT & Embedded
Arduino, Raspberry Pi & sensors
Open AI & Claude
ChatGPT, Claude Code & prompt tips
Maths for CS
Discrete maths, stats & linear algebra
Practice Questions
Topic-wise coding problems
Mock Interviews
Simulate real interview rounds
OOP Challenges
Java OOP design exercises
SQL Playground
Write & test queries live
Road Map Tracker
Follow structured learning paths
21 subjects, 419+ MCQs. Pick a topic, answer at your own pace, and get an instant explanation after every question.
Syntax, data types, functions & core idioms.
OOP fundamentals, JVM internals & collections.
Pointers, memory management & low-level basics.
Classes, STL, memory model & polymorphism.
Closures, async, the DOM & array methods.
Semantic markup, forms, media & structure.
Box model, flexbox, specificity & positioning.
Complexity, trees, graphs, sorting & search.
Processes, scheduling, memory & deadlocks.
OSI/TCP layers, protocols & addressing.
Search, agents, heuristics & game playing.
Supervised/unsupervised learning & evaluation.
Neural nets, activations, optimizers & training.
Convolutions, pooling & vision architectures.
Sequences, LSTM/GRU & long-term dependencies.
Tokenization, embeddings, transformers & more.
Events, distributions & Bayes' theorem.
Central tendency, hypothesis testing & spread.
Arrays, broadcasting, shapes & vectorized ops.
DataFrames, Series, grouping & cleaning.
EDA, visualization, wrangling & KPIs.