Language
JavaScript
Dynamic, async-heavy web logic
01 / Features
KEY FEATURES
01
AI-Powered Feedback
Instant, detailed analysis of how well you actually understood the code
02
Progress Tracking
Comprehensive analytics with per-skill breakdowns and trends
03
Pattern Registry
Your recurring mistakes are tracked over time so you can close your weak spots
04
Real-world Practice
Read and reason about real code snippets across five languages
02 / Practice
HOW IT WORKS
01
Choose Code
Select based on language, difficulty, and topic tags
02
Analyze
Read and explain what the code does in your own words
03
Get Feedback
Receive detailed AI feedback with comprehensive metrics
03 / Principles
EVALUATION AXES
Syntax Understanding
How well you read the code as written
Logic Understanding
How well you trace what the code actually does
Edge Cases
Whether you spot the inputs that break it
Complexity Analysis
Reasoning about performance and cost
04 / Languages
SUPPORTED LANGUAGES
Language
Python
Readable scripting & data work
Language
Java
Typed, object-oriented systems
Language
C
Low-level, memory-close code
Language
SQL
Querying & shaping data