LabDemo - AI Teaching Assistant for CS Labs

Learn to debug, not to copy. LabDemo helps you understand errors in the terminal and gives you tips on how to solve them, rather than directly giving you the solution.

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πŸš€ LabDemo - AI Teaching Assistant for CS Labs

πŸ’₯ Problem Statement

CS students lose 2-6 hours per week decoding cryptic error messages like IndexOutOfRangeException or list index out of range. TAs can't scale to help everyone, and Stack Overflow teaches copying solutions rather than debugging skills.

πŸ› οΈ Solution

Paste assignment + broken code + error β†’ instant ethical hints: πŸ”΄ What broke: "Loop went past array end" (plain English) πŸ’‘ Core concept: "Arrays start at index 0" 🧭 Debug nudge: "Check i <= vs i < condition"

πŸ’‘ Inspiration

Inspired by my own experiences in CS Labs. They would often get busy and getting individual help would often take a very long time.

🌍 Impact

  • 1.2M CS students globally could save 100+ hours/year
  • Ethical alternative to solution-copying sites (uni approved)
  • Scales instantly - no TA hiring needed
  • Covers 95% of intro CS courses (12 languages)

βš™οΈ What It Does

Single-screen web app supporting ** Python, Java, JavaScript, TypeScript, C#, SQL, C, C++, Ruby, Go, Rust, PHP, Kotlin, Swift, R, Scala**:

  1. Paste assignment description
  2. Paste your broken code
  3. Paste console error
  4. Click β†’ 3-second structured hints

Live: https://labdemoai.vercel.app

πŸ”¨ How I Built It

  • Next.js 15 App Router + API routes
  • Groq + Llama 3.1 70B (300+ tokens/sec)
  • Tailwind CSS + shadcn/ui
  • Vercel deployment (global CDN)
  • react-syntax-highlighter (12 languages)

Built solo in 24 hours for CraterHacks 2026.

⚠️ Challenges I Ran Into

  • Next.js 15 build errors (dynamic = 'force-dynamic' fix)
  • next-themes TypeScript import issues (React.ComponentProps fix)
  • Vercel env var propagation
  • API quota management during demo prep

πŸ† Accomplishments I'm Proud Of

  • Fully deployed prototype with 12-language support
  • Live demo handling real CS lab errors instantly
  • Ethical AI design - hints only, teaches debugging
  • Production-ready Vercel deployment with zero-downtime

πŸ“š What I Learned

  • Next.js 15 App Router quirks (export const dynamic)
  • OpenAI-compatible APIs (Groq proxy pattern)
  • Vercel production builds vs dev mode differences
  • Structured LLM prompts for consistent JSON output
  • Tailwind + shadcn/ui = 10x UI speed

πŸš€ What's Next For LabDemo

  • Chrome/VSCode extension integration
  • Te Reo Māori explanations (NZ universities)
  • Course-specific hint libraries
  • Multi-file project analysis
  • Mobile app (iOS/Android)
  • Freemium model for CS departments

William Hernandez
Software Engineering Student
University of Waikato, NZ
CraterHacks 2026 Entry

Built With

  • autoprefixer
  • cursor
  • eslint
  • groq
  • javascript
  • lucide-react
  • next-themes
  • next.js-15
  • node.js
  • pdf-parse
  • postcss
  • react-18
  • react-syntax-highlighter
  • shadcn/ui
  • tailwind-css
  • typescript
  • vercel
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