Prompt Engineering for Developers: Best Framework for Coding (2026)

Role: You are a senior TypeScript developer with expertise in React and Next.js.

Instructions: Create a custom hook for handling form validation with the following requirements:
- Support for multiple field types (text, email, number)
- Real-time validation as users type
- Debounced validation to prevent excessive re-renders
- Clear error messages per field

Steps:
1. Define the TypeScript interfaces for form fields and validation rules
2. Implement the core validation logic
3. Add debouncing using useRef and setTimeout
4. Create the return object with field states and handlers

Expectations:
- Production-ready code with proper TypeScript types
- Include JSDoc comments for the public API
- Provide a usage example in a comment block

This React component causes an infinite re-render loop:

function UserProfile({ userId }) {
  const [user, setUser] = useState(null);

  useEffect(() => {
    fetchUser(userId).then(setUser);
  }, [user]);

  return <div>{user?.name}</div>;
}

Let's debug this step by step:
1. Identify what triggers re-renders
2. Trace the useEffect dependency array
3. Find the cause of the loop
4. Provide the fix

Role: You are a senior developer conducting a thorough code review.

Instructions: Review this pull request for a payment processing function.

Context:
- This handles production payments
- Must be PCI compliant
- Performance matters (called 10K times/day)

[Code to review]

Steps (think through each step by step):
1. Security review: Look for injection, data exposure, authentication issues
2. Error handling: Check for edge cases, proper error messages, logging
3. Performance: Identify potential bottlenecks or N+1 queries
4. Maintainability: Code clarity, naming, documentation
5. Testing: What tests would you add?

Expectations: Provide specific line-by-line feedback with severity levels (critical/major/minor/suggestion).

We need to implement real-time notifications in our web app.

Explore 3 architectural approaches:
1. WebSockets (Socket.io)
2. Server-Sent Events (SSE)
3. Polling with optimistic updates

For each approach:
- Implementation complexity
- Scalability characteristics
- Infrastructure requirements
- Failure modes and fallbacks
- Cost at scale (10K concurrent users)

Evaluate and recommend the best fit for a team with limited DevOps resources but need for reliable delivery.

Role: You are a senior engineer refactoring legacy code to modern standards.

Instructions: Refactor this class-based React component to a functional component with hooks.

Original code:
[paste class component]

Steps:
1. Convert state to useState hooks
2. Convert lifecycle methods to useEffect
3. Replace this.props with destructured props
4. Simplify any complex logic with custom hooks if appropriate

Expectations:
- Maintain identical functionality
- Follow React 18 best practices
- Add TypeScript types
- Keep the same prop interface

Phase 1 (RISE): Generate initial implementation
Phase 2 (CoT): "Review this code step by step and identify issues"
Phase 3 (RISE): "Now fix the identified issues"

First, write comprehensive tests for this function:
[function signature]

Now implement the function to pass all tests.
Show your reasoning as you handle each test case.

I'm stuck on this bug. Let me explain what's happening:
[description]

As I explain, ask me clarifying questions that might help me realize what I'm missing. Think like a senior engineer doing pair debugging.

Write a TypeScript function that validates email addresses.

Requirements:
- Accept a string input
- Return { isValid: boolean, error?: string }
- Check for: @ symbol, valid domain, no spaces
- Handle edge cases: empty string, null/undefined
- Include JSDoc comments

Context: This is for a user registration form in a Next.js app.

Create a REST API endpoint for [RESOURCE] in [FRAMEWORK].

Specifications:
- Method: [GET/POST/PUT/DELETE]
- Route: [ROUTE]
- Authentication: [REQUIRED/OPTIONAL]
- Request body: [DESCRIBE]

Include input validation, error handling, and TypeScript types.

I'm getting this error: [ERROR MESSAGE]

Code:
[YOUR CODE]

Expected behavior: [WHAT SHOULD HAPPEN]
Actual behavior: [WHAT HAPPENS]

Debug step by step:
1. What's the error telling us?
2. What are potential causes?
3. How can we verify each?
4. What's the fix?

Review this code for security vulnerabilities:

[YOUR CODE]

Check for:
- Injection vulnerabilities
- Authentication issues
- Data exposure risks
- Input validation gaps

For each issue: severity, vulnerability, how exploited, recommended fix.

Write unit tests for this function:

[YOUR CODE]

Testing framework: [JEST/PYTEST/etc.]

Include tests for:
- Happy path
- Edge cases
- Error handling
- Boundary conditions