📝 Assessment – HTTP Services in Go

This assessment is designed to evaluate your understanding of building HTTP services in Go, including handler design, JSON processing, middleware, and testing.

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🎯 Assessment Objectives

By completing this assessment, you should be able to:

• Design and implement HTTP handlers
• Handle JSON request/response correctly
• Apply middleware patterns
• Use proper HTTP status codes
• Write clean, testable Go code
• Reason about real-world backend scenarios

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📚 Section 1: Conceptual Questions

Q1. Explain how http.Handler works in Go.

• What is the role of ServeHTTP?
• How does http.HandlerFunc simplify handler creation?

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Q2. Why does Go prefer using the standard library (net/http) over heavy frameworks?

Discuss in terms of:

• Performance
• Simplicity
• Maintainability

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Q3. What is middleware in Go?

• How is it implemented?
• Provide a real-world example (e.g., logging, authentication).

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Q4. Why is explicit error handling preferred in Go HTTP services?

Compare with exception handling in Python.

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Q5. What are the benefits of using context.Context in HTTP services?

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🧩 Section 2: Code Understanding

Q6. Analyze the following code:

```go id=”a1code” func handler(w http.ResponseWriter, r *http.Request) { if r.Method != http.MethodGet { http.Error(w, “Invalid method”, http.StatusBadRequest) return } w.Write([]byte(“OK”)) }

* What is correct in this implementation?
* What improvements would you suggest?

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### Q7. Identify issues in this JSON handler:

```go id="a2code"
func createUser(w http.ResponseWriter, r *http.Request) {
	var user User
	json.NewDecoder(r.Body).Decode(&user)
	w.WriteHeader(200)
}

• List at least 3 problems
• Suggest improvements

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💻 Section 3: Practical Tasks

Q8. Build a Simple HTTP Endpoint

Create an endpoint:

GET /health

Requirements:

• Return status 200 OK
• Response body: "Service is healthy"
• Include proper headers

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Q9. JSON API Implementation

Create an endpoint:

POST /user

Requirements:

• Accept JSON input:

  { "name": "John" }
  

• Return:

  { "message": "User created" }
  

• Handle invalid JSON properly
• Return appropriate status codes

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Q10. Middleware Implementation

Implement a logging middleware that:

• Logs HTTP method and path
• Wraps an existing handler

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🧪 Section 4: Testing

Q11. Write a test for the /health endpoint:

• Validate status code
• Validate response body

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Q12. Write a table-driven test for /user endpoint:

• Valid request
• Invalid JSON
• Empty body

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🧠 Section 5: Design & Scenario-Based Questions

Q13. How would you structure a production-ready Go HTTP service?

Discuss:

• Project structure
• Separation of concerns
• Dependency injection

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Q14. A service is experiencing high latency. What areas would you investigate?

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Q15. How would you handle graceful shutdown in a production Go service?

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📊 Evaluation Criteria

Area	Weightage
Conceptual Understanding	20%
Code Quality	25%
Correctness	25%
Testing	15%
Design Thinking	15%

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💡 Mentor Notes

• Focus on clarity and correctness over complexity
• Encourage idiomatic Go patterns

• Look for:

  • Proper error handling
  • Clean handler design
  • Thoughtful testing

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📌 Key Takeaway

This assessment is not just about writing code—it’s about thinking like a Go backend engineer.

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