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Utkarsh Rastogi
Utkarsh Rastogi

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I Built a Serverless AI Summarizer That Blocks Harmful Content on AWS

How it started

We've all done it — paste something into ChatGPT without thinking twice. Sometimes that "something" has a phone number, an email, or worse.

There's nothing stopping it. No safety check. No filter.

I thought — what if the AI had a security guard? Something that checks every input before the AI sees it, and every output before the user sees it.

So I built it.


What it does

AI Content Guard — a text summarizer with a safety layer.

  • Normal text → clean 2-3 line summary ✅
  • Phone/email/name in text → hidden as {PHONE}, {EMAIL}, {NAME}, summary still generated ✅
  • Credit card / SSN → fully blocked, AI never sees it 🚫
  • Hate speech, violence, prompt attacks → blocked instantly 🚫

The guardrail runs twice — once on your input, once on the AI's output. Safety before and after.


Architecture

AI Content Guard Architecture

The flow:

User → Amplify (React UI) → API Gateway → Lambda
  → Guardrail INPUT check (block or continue)
  → Bedrock AI Model (generates summary)
  → Guardrail OUTPUT check (block or continue)
  → DynamoDB (log result)
  → Response back to user
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Blocked = 0.4 seconds. Success = 1.5 seconds.
Blocked is faster because the AI model is never called.


Why serverless?

  • No servers to manage or patch
  • Pay nothing when nobody's using the app
  • Auto-scales if 100 people hit it at once
  • Deploy with one command, tear down with one command

I write code. AWS runs it. That's the deal.


The stack

Service What it does
Lambda (Python 3.12) Runs the logic
Bedrock (Nova Lite) AI summarization
Bedrock Guardrails Content safety + PII detection
API Gateway REST API with rate limiting
DynamoDB Audit logs (auto-deletes in 30 days)
SSM Parameter Store Config without redeployment
Amplify Hosts the React frontend
CloudFormation Infrastructure as Code (6 templates)

Why guardrails matter

This isn't academic. It's a real requirement now.

  • Samsung banned ChatGPT after employees leaked code into it.
  • EU AI Act requires safety measures. No guardrails = non-compliant.
  • India's DPDP Act makes you liable for unprotected personal data.
  • One screenshot of your chatbot generating hate speech = your product is dead.

Guardrails solve this at infrastructure level. You don't ask the AI to be safe. You put a wall in front of it.


For students & early-career devs

This project covers what actually comes up in interviews:

  • "Have you worked with serverless?" → Yes. Lambda, API Gateway, DynamoDB.
  • "How do you handle security?" → Least-privilege IAM, encryption, defense in depth.
  • "Tell me about an AI project." → Built a summarizer with guardrails for content safety.
  • "How do you deploy?" → Infrastructure as Code. One command.

Companies like Razorpay, CRED, Swiggy use the exact same services. Same patterns. Different scale.

My honest advice: Don't just read this. Clone it. Deploy it. Break something. Fix it.

Nobody cracked an interview by reading about Lambda. They cracked it by using Lambda. Hands-on is the only thing that sticks.


Try it

Live app: https://main.d1244888rwbz47.amplifyapp.com

Source code: https://github.com/Utkarshlearner/ai-content-guard

Run your own:

git clone [your-repo-url]
cd ai-content-guard
./deploy.sh all
./deploy-frontend.sh
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5 minutes. Done.


What I learned

  1. Safety is infrastructure, not prompt engineering.
  2. Blocked is faster than success (fewer API calls).
  3. ANONYMIZE ≠ BLOCK — know when to be strict vs lenient.
  4. Config (SSM) and code (Lambda) should live separately.
  5. "We'll add safety later" is how companies end up in the news.

About me

I'm Utkarsh. I build on AWS and write about it.


🚀 Your turn

What would you add? Cognito login? Hindi support? Admin dashboard? Slack bot?

Fork it. Build something. Tag me.

Or just drop your ideas in the comments — I'm picking the best ones for the next version.


Build with AI. But build safe. 🛡️

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