Introduction to Debug Arena

Debug Arena is a secure, real-time competitive debugging platform designed for live coding events and hackathons. Built using Flask and Python, the system challenges participants to solve progressive levels of logical and syntactical bugs within a strictly controlled environment. The platform integrates automated code evaluation, a persistent anti-cheat system, and dynamic scoring to facilitate fair competition.

Sources: README.md:1-10

System Architecture

The Debug Arena follows a multi-layered architecture where the frontend serves an interactive IDE (CodeMirror), and the backend handles secure code execution and state management.

Architectural Overview

The system is divided into several core modules:

• Authentication Layer: Manages team registration and session-based access.
• Proctoring System: A JavaScript-based security layer that monitors user behavior.
• Evaluation Engine: Executes Python code in a subprocess with strict safety constraints.
• Scoring & Persistence: Tracks team progress, time taken, and penalties using SQLAlchemy.

The following diagram illustrates the high-level data flow from the client to the evaluation engine:

Core Components

1. Level Management and Content

Levels are defined in a centralized manager that specifies the title, buggy source code, expected output, and difficulty. Each level includes a specific hint that, when accessed, applies a pre-defined point penalty.

Sources: levels/level_manager.py:3-108, routes/arena_routes.py:35-42

2. Evaluation and Security Engine

The platform uses a subprocess to execute user-submitted code safely. Before execution, a security utility scans the code for forbidden keywords such as import os, eval(, or .system( to prevent shell injection or unauthorized system access.

3. Proctoring and Anti-Cheat System

The proctor.js module enforces event integrity by monitoring fullscreen status and tab visibility. The system allows a maximum of 3 violations before a team is automatically disqualified.

• Fullscreen Enforcement: Users must play in fullscreen mode; exiting triggers a violation.
• Tab Switching: Detecting visibilitychange (switching tabs) logs a violation to the database.
• Persistent Tracking: Violations are stored in the Team model, preventing bypass via page refreshes.

Sources: static/js/proctor.js:1-75, routes/arena_routes.py:108-128

Scoring Logic

The scoring system calculates points based on completion speed and usage of the "Oracle" hint system.

1. Base Score: 100 points per level.
2. Time Penalty: 1 point is deducted for every 10 seconds elapsed (time_taken // 10).
3. Hint Penalty: If a hint is used, the level's specific penalty value is subtracted.
4. Hard Minimum: Regardless of penalties, the minimum score for a successful level completion is 30 points.

Sources: routes/submit_routes.py:44-60

Data Model

The application uses SQLAlchemy to manage team states and submission history.

Conclusion

Debug Arena provides a robust infrastructure for competitive programming by combining secure code execution with active proctoring. By centralizing level logic in the level_manager and enforcing security through both static analysis and runtime constraints, the platform ensures a fair and challenging environment for participants to demonstrate their Python debugging proficiency.