MAJOR06 / 10

Online Compiler

Multi-language cloud code execution sandbox with admin monitoring dashboard, regex-based security scanning, and real-time WebSocket output streaming.

FlaskWebSocketNode.jsPythonDockerRegex

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Solo Project

// Problem Statement

The Challenge

Existing online compilers batch-process code and return output only after completion. They lack real-time streaming, admin observability, and security isolation for educational environments.

No real-time output — users wait for full execution before seeing any output
No admin monitoring — no way to see what code is being executed across the platform
Security risk — users can run harmful system commands (rm -rf, fork bombs, network access)
No system usage visibility — no CPU/memory monitoring for resource-heavy executions

// My Approach

Engineering Thinking

Built a two-application system: the compiler frontend/backend for code execution, and a separate admin dashboard for monitoring all executions, system resources, and security alerts.

The security layer uses regex pattern matching to detect harmful code patterns before execution — system calls, filesystem operations, network access, and infinite loop patterns. Flagged code is blocked and logged for admin review.

Supports all text-based languages (Python, C, C++, Java, Go, Rust, etc.) and HTML/CSS/JS for web preview. UI-based frameworks like Flutter, Swift, React are excluded since they need build toolchains beyond simple compilation.

CHOSEN

Separate admin dashboard + compiler

Decoupled monitoring from execution. Admin sees all sessions, resource usage, and security flags in real-time.

CHOSEN

Regex pre-execution security scan

Pattern-match dangerous code before it runs. Block system calls, fork bombs, and network access attempts.

// Technical Deep-Dive

Key Systems

Multi-Language Execution Engine

10+ languages: Python, C, C++, Java, Go, Rust, JS, etc.
HTML/CSS/JS web preview with sandboxed iframe
Phase-based execution: Init → Compile → Execute → Done
Memory/timeout limits per execution session

Admin Monitoring Dashboard

Real-time view of all active execution sessions
CPU and RAM usage monitoring per process
Security alert feed with flagged code snippets
Force-terminate capability for runaway processes

Regex Security Scanner

Pre-execution pattern matching for dangerous code
Detects: system(), exec(), rm, fork bombs, network calls
Flagged code blocked + logged for admin review
Language-specific rule sets for each supported language

WebSocket Streaming

Persistent WebSocket per session
stdout/stderr streamed line-by-line in real-time
Execution phase updates pushed to frontend
Admin dashboard receives all streams simultaneously

// Challenges & Failures

What Broke & What I Learned

Challenge 01

Regex Can't Catch Everything

Regex-based security scanning catches known patterns, but obfuscated code can bypass it — base64 encoded system calls, dynamic imports, and eval() chains. Had to layer regex with process-level sandboxing (restricted filesystem + network) for defense in depth.

Lesson: Static analysis is necessary but not sufficient. Always combine with runtime isolation for true security.

Challenge 02

WebSocket Scaling with Concurrent Users

Each code execution opens a persistent WebSocket connection. With multiple concurrent users, the server had to manage dozens of streams simultaneously while keeping admin dashboard updated in real-time. Required careful connection pooling and message routing.

Lesson: WebSocket servers need explicit connection lifecycle management. Unlike HTTP, connections persist and consume resources continuously.

// Results & Impact

What It Achieved

Outcome

10+ Language Support

Full compilation and execution for all major text-based programming languages plus HTML/CSS/JS web preview.

Outcome

Dual Application Architecture

Separate admin monitoring dashboard with real-time visibility into all code executions, system resources, and security alerts.

Outcome

Security-First Design

Multi-layer security: regex pre-scan + sandboxed execution + resource limits + admin force-terminate.

// Demo & Evidence

Screenshots

Code Editor — Multi-Language Execution

*Note: These images are generated by AI, the images will be replaced new very soon

Admin Dashboard — Execution Monitoring & Security Alerts

*Note: These images are generated by AI, the images will be replaced new very soon