Master coding assessments
the way you actually learn.
50 progressive Python problems. A live AI companion that coaches you in real time. Roundtable discussions where AI companions debate concepts out loud.
Everything you need to prepare
Not just another problem set. A complete practice platform with AI built in.
Performance Insights
A calibrated 0-100 readiness score from 6 weighted signals. Know exactly where you stand.
Roundtable Discussions
Watch AI companions debate coding concepts out loud. You learn by listening to experts think.
Systems Lab — 20 Architectures
Ten backend engineering systems + ten AI research systems. Each with components, data flow, trade-offs, starter code, and companion commentary.
AI Companion
A draggable companion that lives on every page. It reads your code and gives contextual help.
Real Python in Browser
Write and run Python via Pyodide — no install, no server. Your code never leaves your device.
90-Minute Simulation
A timed run that mirrors the real assessment. Pick a problem, complete all 5 levels, beat the clock.
Drills, Quizzes & Jobs
Targeted skills drills, concept quizzes, and curated AI safety + fellowship job listings.
Four AI minds. One conversation.
Each companion has a distinct voice and perspective. In Roundtable mode, they discuss coding topics with each other — you watch and learn.
Calm, foundational. Asks 'why?' and focuses on first principles.
Pragmatic senior engineer. Asks 'what's the trade-off?' and surfaces real-world concerns.
Curious learner. Asks the 'dumb' questions everyone else is afraid to.
Systems architect. Asks 'how does this scale?' and connects problems to larger patterns.
From zero to assessment-ready
A 7-day path from foundations to assessment-ready. Each day builds on the last.
Practice
Pick any problem family. Write Python in the browser. Run visible unit tests. The companion watches and gives contextual hints.
Analyze
Your readiness score updates after every run. See your mastery heatmap, recurring error patterns, and adaptive recommendations.
Simulate
When you're ready, run a 90-minute simulation. One problem, 5 levels, real pressure.
Watch companions think out loud
A real roundtable conversation — companions ask each other questions, disagree, and build on answers.
Ready to start?
No signup. No install. Just open a problem and start writing Python. Your progress is saved locally.