AI Pair Programming: Advanced Collaboration Patterns

Layer 1: Project Context
"This is a Next.js 15 e-commerce app using TypeScript, Prisma, and Stripe."

Layer 2: Domain Context  
"We're working on the checkout flow. Users add items to cart, 
enter shipping info, and pay with Stripe."

Layer 3: Task Context
"I need to implement the shipping address validation 
with USPS API integration."

Layer 4: Constraints
"Must handle PO boxes, international addresses, and 
return user-friendly error messages."

// Show AI an existing pattern
"Here's how we handle API routes in this project:

// src/app/api/products/route.ts
export async function GET(request: Request) {
  const { searchParams } = new URL(request.url);
  const category = searchParams.get('category');
  
  const products = await prisma.product.findMany({
    where: category ? { category } : undefined,
  });
  
  return Response.json({ data: products });
}

Now create a similar route for orders with pagination."

Step 1: "Create the interface and function signature for 
        a ShippingCalculator class"

Step 2: "Implement the calculateRate method using 
        the FedEx API"

Step 3: "Add error handling for network failures 
        and invalid addresses"

Step 4: "Add caching with a 1-hour TTL"

"Review the code you just generated for:
1. Security vulnerabilities
2. Performance issues  
3. Edge cases not handled
4. TypeScript strict mode compliance

Then provide an improved version."

"Provide three different approaches to implement 
rate limiting:
1. In-memory with Map
2. Redis-based distributed
3. Token bucket algorithm

Compare trade-offs for each."

"I'm seeing this error when submitting the form:

Error: Cannot read property 'email' of undefined
  at validateUser (src/lib/validation.ts:24)
  
Here's the relevant code:
[paste code]

The form data looks correct in DevTools. 
Help me trace where the data gets lost."

"I need to decide between two approaches for 
handling real-time notifications:

Option A: WebSockets with Socket.io
Option B: Server-Sent Events

Our requirements:
- 10,000 concurrent users
- Messages are server→client only
- Must work behind corporate proxies
- Deployed on Vercel

Walk me through the trade-offs."

"Act as a senior security engineer reviewing this 
authentication implementation. Identify vulnerabilities 
and suggest fixes with code examples."

"Implement this feature with the following constraints:
- No external dependencies
- Must work in Node.js 18+
- Maximum 50 lines of code
- Must be testable without mocking"

"Explain this regex pattern step by step, then 
show me how to modify it to also match 
international phone numbers:

/^\+?1?[-. ]?\(?\d{3}\)?[-. ]?\d{3}[-. ]?\d{4}$/"

Bad: "Here's my 500-line file, fix it"
Good: "Here's the specific function that's failing [paste]. 
      The expected behavior is X but I'm getting Y."

Bad: "Make this better"
Good: "Refactor this function to:
      - Reduce cognitive complexity
      - Handle null cases
      - Add TypeScript strict types"

Bad: Copy-paste without review
Good: "Let me verify this handles the edge case 
      where the user array is empty..."

"Starting a new coding session. Context:
- Project: E-commerce checkout refactor
- Today's goal: Implement guest checkout flow
- Key files: src/app/checkout/*, src/lib/cart.ts
- Constraints: Must maintain backward compatibility"

"Continuing from earlier - we implemented the 
address form. Now let's add the payment step. 
Remember we're using Stripe Elements and 
need to handle 3D Secure."

"Before we end, summarize:
1. What we implemented
2. What's left to do
3. Any technical debt we introduced
4. Suggested next steps"