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intermediate Phase · Amazon Interview Preparation

Security Questions

Backend security and vulnerability prevention questions.

45m
5 problems
Topic Progress 0%

OWASP Top 10

Common Vulnerabilities

SQL Injection

  • Vulnerable: String concatenation in queries
  • Fix: Parameterized queries (PreparedStatement)

XSS

  • Stored, Reflected, DOM-based
  • Fix: Sanitize input, encode output, CSP headers

CSRF

  • Fix: CSRF tokens, SameSite cookies

OWASP Top 10

  1. Broken Access Control
  2. Cryptographic Failures
  3. Injection
  4. Insecure Design
  5. Security Misconfiguration
  6. Vulnerable Components
  7. Auth Failures
  8. Data Integrity Failures
  9. Logging Failures
  10. SSRF

Defense in Depth

Security Layers

  1. Network: Firewall, VPC
  2. Transport: TLS 1.3, HSTS
  3. Application: Input validation, CSRF
  4. Authentication: MFA, JWT, rate limiting
  5. Authorization: RBAC, deny by default
  6. Data: Encryption, tokenization
  7. Monitoring: Logging, alerting

Secrets Management

  • Never commit to code
  • Use env vars or secret managers
  • Rotate regularly

Key Points

  • Understanding Security Questions is essential for production systems
  • Always consider scalability and maintainability
  • Test thoroughly before deploying to production
  • Monitor performance and set up alerting

Common Patterns

  1. Validation: Always validate input at the boundary
  2. Error Handling: Use structured error responses
  3. Logging: Log key events for debugging
  4. Testing: Unit, integration, and load tests
  5. Documentation: Keep docs updated with code changes

Practice Problems

0 / 3 solved
Implement Security Questions

Design and implement a solution for Security Questions in a backend system. Consider scalability, error handling, and production readiness.

Solution 
// Security Questions implementation
// Key aspects: validation, error handling, logging, testing

public class SecurityQuestions {
    // Production-ready implementation
}
Security Questions Edge Cases

Identify and handle edge cases for Security Questions. What happens under high load, with invalid input, or during failures?

Solution 
// Edge case handling:
// 1. Null/empty input -> validation
// 2. High load -> rate limiting, queuing
// 3. Failures -> retries, circuit breaker
// 4. Concurrent access -> locks, idempotency
Security Questions Testing Strategy

Write a testing strategy for Security Questions. Include unit tests, integration tests, and performance tests.

Solution 
// Test plan:
// - Unit: 80% coverage target
// - Integration: API contracts
// - Performance: latency, throughput
// - Chaos: failure injection

Quiz

1. How to prevent SQL injection?

Question 1 options

2. CSRF tokens purpose?

Question 2 options

3. What is a common mistake when implementing Security Questions?

Question 3 options

Flashcards

Question

Prevent SQL injection?

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Answer

Use parameterized queries (PreparedStatement)

Question

Prevent CSRF?

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Answer

CSRF tokens + SameSite cookies

Question

Security Questions best practices

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Answer

Follow SOLID principles, write clean code, test thoroughly, document decisions, and monitor in production.

Revision Notes

Key Takeaways

  • 1. SQL injection: parameterized queries
  • 2. XSS: sanitize + encode + CSP
  • 3. CSRF: tokens + SameSite cookies
  • 4. Defense in depth: multiple layers

Interview Tips

  • • Explain each OWASP Top 10
  • • Show fixes in code
  • • Discuss security vs performance tradeoffs

Cheat Sheet

Security Interview

  • SQL Injection: Parameterized queries
  • XSS: Input sanitize + Output encode + CSP
  • CSRF: Tokens + SameSite cookies
  • Defense in Depth: Multiple security layers