Challenges
Choose your challenge. Prove your worth.
Fix the Broken Calculator
Clone the repo, fix the bugs, push a green build
demo-git
TODO: one-liner for task cards
Multi-Tenant Cluster Outage
Restore one tenant's portal without breaking the healthy tenant
Supply Chain Containment
Clean a compromised release pipeline without breaking the artifact
Stabilize the Support RAG System
Repair a broken support RAG pipeline with stale docs, prompt injection, and weak grounding
Repair the Live Collaboration Board
Fix optimistic updates and reconnect logic in a real-time board client
Repair the Billing Ledger
Fix an event-sourced billing ledger that breaks under retries, refunds, and chargebacks
Fix the BookStore
Restore a broken multi-service Kubernetes application
Shortest Path in a Blocked Maze
Find the shortest path from S to E in a grid maze
Maximize Unique Characters
Select words to maximize unique characters with no repeats
Hangman
Fix hangman game logic and implement scoring
Chatroom Message
Fix bugs in a linked-list chat buffer
Card Game
Fix card hand scoring and comparison
Empty the Deck
Fix bugs and implement solver for the Sum-15 card game
Clear the Grid: Sum to 15
Implement the Fifteen Sum Card Grid game
Fix the Maze Game
Debug movement logic and implement scoring in a maze game
Filesystem Snapshot Analyzer
Fix bugs in an in-memory filesystem tree analyzer
Email Inbox
Fix bugs in an email mailbox model
Ads Analytics Engine
Fix and implement ad campaign metrics
VLIW Kernel Optimization
Optimize a tree traversal kernel on a custom VLIW SIMD processor
Fix the Broken Deployment
Debug and fix a failing Kubernetes deployment
FizzBuzz
Implement classic FizzBuzz