Fastly Certification Interview Questions and Answers [2025]

Fastly Certification Fundamentals

1. What is Fastly's core platform and its key components?

Fastly is an edge cloud platform designed for real-time content delivery and computing at the edge. Its core components include the CDN for caching and acceleration, VCL (Varnish Configuration Language) for custom request/response handling, Compute@Edge for serverless WebAssembly functions, Next-Gen WAF for security, and DDoS protection for availability. Fastly's global network of 100+ PoPs enables low-latency delivery, while APIs and Terraform integration support DevOps automation. For certification, understanding how these components interact to optimize performance and security is essential.

Explore how real-time DevOps aligns with Fastly certification.

2. Why is Fastly certification valuable for DevOps professionals?

Fastly certification validates expertise in edge computing, VCL scripting, and security features, enhancing career prospects for DevOps roles focused on performance and resilience. It demonstrates proficiency in integrating Fastly with CI/CD pipelines, optimizing CDN configurations, and mitigating threats at the edge, making certified professionals indispensable for building scalable, secure applications in modern cloud-native environments.

3. When should Fastly be deployed in certification scenarios?

• For accelerating APIs and static assets in CI/CD workflows.
• During DDoS protection testing for application resilience.
• When implementing WAF rules for endpoint security validation.
• For optimizing media streaming in global delivery tests.
• In multi-cloud setups for unified edge management.
• During compliance audits for data residency verification.
• For scaling high-traffic events with real-time monitoring.

4. Where does Fastly's edge network provide certification-level value?

Fastly's edge network, with 100+ Points of Presence (PoPs), processes traffic close to users for sub-50ms latency, critical for certification scenarios involving global content delivery. It enables real-time VCL and Compute@Edge execution, supporting DevOps automation for dynamic configurations.

This distributed architecture ensures certification-ready scalability.

5. Who typically pursues Fastly certification?

• DevOps Engineers: To automate edge configurations in pipelines.
• SREs: For reliability and incident response at the edge.
• Security Specialists: To master WAF and DDoS mitigation.
• Platform Architects: For designing scalable edge infrastructure.
• Developers: For Compute@Edge and VCL scripting expertise.
• Compliance Officers: To ensure edge data governance.
• Teams: For collaborative certification in edge projects.

6. Which Fastly services are central to certification?

Fastly's certification focuses on CDN for delivery, VCL for customization, Compute@Edge for serverless, Next-Gen WAF for security, and DDoS protection for availability. These services integrate with DevOps tools, requiring knowledge of automation, optimization, and troubleshooting for certification success.

7. How does Fastly integrate with CI/CD for certification?

Fastly integrates with CI/CD via APIs for automated VCL uploads, cache purges, and WAF rule updates. Terraform providers enable IaC for configurations, while webhooks trigger notifications in Jenkins or GitHub Actions. For certification, understanding these integrations ensures automated, secure deployments in edge environments.

8. What is VCL in Fastly, and why is it certified knowledge?

VCL (Varnish Configuration Language) is Fastly's domain-specific language for customizing request/response handling, caching, and routing at the edge. Certification requires mastering VCL syntax for if/else logic, subroutines, and variables, enabling advanced scenarios like header manipulation or geo-based delivery. VCL compiles to bytecode for high performance, integrating with DevOps for version-controlled scripting in CI/CD pipelines.

Learn how GCP DevOps uses VCL for edge scripting.

9. Why is Fastly's DDoS protection certified essential?

Fastly's DDoS protection is certified essential for its autonomous mitigation at the edge, absorbing attacks without configuration. It supports always-on protection and real-time analytics, integrating with CI/CD for automated responses. Certification covers understanding attack types and mitigation strategies for high-availability applications.

10. When to enable Fastly's Next-Gen WAF in certification tests?

• For protecting APIs and web apps from OWASP threats.
• Implementing rate limiting for endpoint security.
• Validating schemas during CI/CD testing.
• Securing production endpoints dynamically.
• Ensuring API policy compliance.
• Detecting real-time threats with ML.
• Integrating with DevOps pipelines for automation.

11. What is Compute@Edge, and its certification scope?

Compute@Edge is Fastly's serverless platform for running WebAssembly (Wasm) modules at the edge, supporting languages like Rust and JavaScript. Certification covers deploying Wasm for custom logic, integrating with KV storage, and handling stateful applications. It enables low-latency personalization and security, with DevOps automation via APIs for CI/CD integration.

12. Why deploy Fastly Spectrum for certification?

Fastly Spectrum secures non-HTTP protocols like SSH and TCP, protecting apps from DDoS with edge delivery. Certification emphasizes its role in securing IoT and custom apps, with real-time mitigation and analytics for DevOps monitoring.

13. When to use Fastly's Rate Limiting in certification?

• Protecting APIs from abuse and overload.
• Preventing brute force attacks on endpoints.
• Throttling high-traffic endpoints dynamically.
• Securing CI/CD deployments from threats.
• Ensuring API usage compliance.
• Managing real-time traffic spikes.
• Blocking bot-driven requests automatically.

14. Where does Fastly's Zero Trust Access fit in certification?

Fastly's Zero Trust Access enforces secure app access via IdPs, replacing VPNs. Certification covers SSO integration, least privilege policies, and logging for compliance, essential for DevOps securing remote access in production.

It ensures secure, scalable access.

15. Who pursues Fastly certification for security?

• DevOps Engineers: Automate WAF and DDoS in pipelines.
• Security Specialists: Configure Next-Gen WAF rules.
• SREs: Monitor threat mitigation metrics.
• Platform Architects: Design secure edge infrastructure.
• Developers: Implement edge security logic.
• Compliance Officers: Ensure security compliance.
• Teams: Collaborate on security workflows.

Discover how cloud security aligns with Fastly certification.

16. Which Fastly protocols are certified for security?

Fastly certifies security for HTTP/HTTPS, TCP, UDP, and DNS with edge-based WAF and DDoS protection. Certification requires understanding protocol optimization, encryption, and threat mitigation for DevOps-managed applications.

17. How optimize Fastly CDN for certification?

Fastly CDN optimization for certification involves VCL for custom caching, shielding for origin offload, and Compute@Edge for dynamic logic. Integrate with CI/CD for automated updates, monitor with analytics for cache hits, and ensure compliance with data residency, demonstrating scalable performance knowledge.

18. What is Fastly Shielding in certification?

• Reduces origin server load by routing to parent PoP.
• Improves cache hit ratios for efficiency.
• Integrates with DevOps for automation.
• Provides real-time analytics for monitoring.
• Scales for global content delivery.
• Reduces latency in high-traffic scenarios.
• Supports certification scenarios for performance.

19. Why use Fastly Load Balancing for certification?

Fastly Load Balancing ensures high availability with health checks and failover, certified for DevOps scenarios requiring zero-downtime deployments and real-time traffic management.

20. When enable Fastly's Bot Management in certification?

• Detecting malicious bot traffic targeting APIs.
• Preventing automated abuse in production.
• Throttling bot requests dynamically.
• Securing CI/CD endpoints from bots.
• Ensuring API usage compliance.
• Managing bot challenges in real-time.
• Blocking sophisticated bots with ML.

21. What is Fastly's Next-Gen WAF for certification?

Fastly's Next-Gen WAF uses ML for anomaly detection and custom rules for threat protection, certified for securing web apps and APIs. It integrates with CI/CD for automated updates and provides real-time intelligence, essential for DevOps security certification.

22. Why use Fastly for SSL/TLS in certification?

Fastly's SSL/TLS supports free certificates, automatic encryption, and custom ciphers, certified for securing DevOps traffic with real-time configuration and compliance.

Explore how Azure DevOps certifies SSL integration.

23. When configure VCL snippets for certification?

• Customizing request/response handling at the edge.
• Rewriting URLs for SEO and performance.
• Redirecting traffic dynamically for failover.
• Securing staging environments with rules.
• Adding security headers for compliance.
• Optimizing performance with custom logic.
• Ensuring regional compliance with geo-rules.

24. Where deploy Fastly Compute for certification?

Fastly Compute deploys WebAssembly for serverless edge functions, certified for low-latency execution in DevOps scenarios like personalization and security.

It supports global scalability.

25. Who pursues Fastly certification for edge computing?

• DevOps Engineers: Automate edge deployments in CI/CD.
• SREs: Ensure edge reliability and uptime.
• Developers: Build Compute@Edge applications.
• Platform Architects: Design scalable edge infrastructure.
• Security Specialists: Implement edge security logic.
• Product Managers: Optimize edge user experience.
• Teams: Collaborate on edge certification projects.

26. Which Fastly services are certified for security?

Next-Gen WAF, DDoS protection, Rate Limiting, and Bot Management are certified for edge security, integrating with DevOps for automated protection and real-time threat mitigation.

27. How optimize Fastly CDN for certification?

Fastly CDN optimization for certification involves VCL for caching, shielding for offload, and Compute@Edge for dynamic content. Integrate with CI/CD for updates, monitor with analytics for hits, and ensure compliance with data residency, demonstrating scalable performance expertise.

28. What is Shielding in Fastly?

• Reduces origin load by routing to parent PoP.
• Improves cache hit ratios for efficiency.
• Integrates with DevOps automation.
• Provides real-time analytics for monitoring.
• Scales for global content delivery.
• Reduces latency in high-traffic.
• Supports certification performance scenarios.

29. Why use Fastly Load Balancing for certification?

Fastly Load Balancing ensures high availability with health checks and failover, certified for zero-downtime DevOps deployments and traffic management.

30. When enable Bot Management for certification?

• Detecting malicious bot traffic targeting APIs.
• Preventing automated abuse in production.
• Throttling bot requests dynamically.
• Securing CI/CD endpoints from bots.
• Ensuring API usage compliance.
• Managing bot challenges in real-time.
• Blocking sophisticated bots with ML.

Learn how advanced DevOps manages bots.

31. What is Next-Gen WAF?

• Advanced WAF for threat protection.
• Uses ML for anomaly detection.
• Supports custom rules for precision.
• Integrates with DevOps pipelines.
• Provides real-time threat intelligence.
• Blocks attacks at the edge.
• Logs for compliance auditing.

32. Why use Fastly for SSL/TLS?

Fastly provides free SSL, automatic encryption, and custom ciphers for secure DevOps traffic.

33. When configure VCL snippets?

• Customizing request/response handling at the edge.
• Rewriting URLs for SEO and performance.
• Redirecting traffic dynamically for failover.
• Securing staging environments with rules.
• Adding security headers for compliance.
• Optimizing performance with custom logic.
• Ensuring regional compliance with geo-rules.

34. Where deploy Fastly Compute?

Fastly Compute deploys WebAssembly for serverless edge functions, certified for low-latency execution in DevOps scenarios.

It supports global scalability.

35. Who uses Fastly Images?

• Developers for image optimization.
• DevOps for asset delivery.
• Security for image scanning.
• Platform teams for CDN integration.
• Product for user experience.
• Compliance for data residency.
• Teams for asset workflows.

36. Which Fastly analytics?

Traffic, Security, and Real User Monitoring for DevOps insights and optimization.

37. How use Fastly API?

• Automates zone configurations with tokens.
• Integrates with Terraform for IaC.
• Scripts WAF updates in CI/CD.
• Monitors via API for alerting.
• Triggers webhook notifications.
• Supports bulk operations for scaling.
• Secures with scoped API keys.

38. What is Fastly's Domain Management?

• Manages secure domain registration.
• Provides WHOIS privacy.
• Integrates with DNS management.
• Supports automated transfers.
• Monitors domain threats.
• Automates renewals for compliance.
• Enables DevOps domain automation.

39. Why use Fastly DNS?

Fastly DNS resolves queries with speed, DDoS protection, and automation for DevOps networks.

40. When enable Under Attack?

• Mitigating DDoS attacks dynamically.
• Responding to real-time threats.
• Implementing JS challenges.
• Protecting CI/CD deployments.
• Safeguarding high-traffic events.
• Ensuring security compliance.
• Blocking malicious traffic.

41. What is Fastly Access?

• Zero Trust for secure app access.
• Integrates with SSO providers.
• Enforces least privilege policies.
• Logs access for auditing.
• Scales for enterprise users.
• Replaces VPN for remote work.
• Verifies identities in real-time.

42. Why use Fastly Gateway?

Gateway filters DNS/HTTP traffic, blocking threats for secure DevOps network access.

43. When configure Firewall Rules?

• Controlling IP-based access.
• Blocking by country or agent.
• Filtering malicious traffic.
• Automating rules in CI/CD.
• Ensuring data law compliance.
• Responding to real-time threats.
• Managing bot traffic.

44. Where use Fastly Cache?

Fastly Cache stores static assets at edge, reducing origin load for DevOps performance.

Supports dynamic purging.

45. Who uses Fastly Analytics?

• DevOps for traffic metrics.
• Security for threat insights.
• SREs for uptime monitoring.
• Platform teams for analysis.
• Developers for optimization.
• Compliance for audit logs.
• Product for user behavior.

Explore how interview prep covers analytics.

46. Which encryption features?

TLS 1.3, custom certificates, and cipher suites for secure DevOps traffic.

47. How support GitOps?

• Uses Terraform for IaC.
• Versions configs in Git.
• Automates CI/CD deployments.
• Triggers webhooks for events.
• Secures pipeline integrations.
• Supports ArgoCD workflows.
• Scales for GitOps automation.

48. What is Fastly Shielding?

• Reduces origin server load.
• Routes traffic to parent PoP.
• Improves cache hit ratios.
• Integrates with DevOps.
• Provides real-time analytics.
• Scales for global delivery.
• Reduces latency significantly.

49. Why use Fastly Load Balancing?

Fastly Load Balancing ensures high availability with health checks and failover for DevOps.

50. When enable Bot Management?

• Detecting malicious bot traffic.
• Preventing automated abuse.
• Throttling bot requests.
• Securing CI/CD endpoints.
• Ensuring API compliance.
• Managing bot challenges.
• Blocking sophisticated bots.

51. What is Next-Gen WAF?

• Advanced WAF for threat protection.
• Uses ML for anomaly detection.
• Supports custom rules.
• Integrates with DevOps.
• Provides real-time intelligence.
• Blocks attacks at edge.
• Logs for compliance auditing.

52. Why use Fastly for SSL/TLS?

Fastly provides free SSL, automatic encryption, and custom ciphers for secure DevOps traffic.

53. When configure VCL snippets?

• Customizing request/response handling.
• Rewriting URLs for optimization.
• Redirecting traffic dynamically.
• Securing staging environments.
• Adding security headers.
• Optimizing performance.
• Ensuring regional compliance.

54. Where deploy Fastly Compute?

Fastly Compute deploys WebAssembly for serverless edge functions in DevOps.

It supports low-latency execution.

55. Who uses Fastly Images?

• Developers for image optimization.
• DevOps for asset delivery.
• Security for image scanning.
• Platform teams for CDN integration.
• Product for user experience.
• Compliance for data residency.
• Teams for asset workflows.

56. Which Fastly analytics?

Traffic, Security, and Real User Monitoring for DevOps insights and optimization.

57. How use Fastly API?

• Automates zone configurations with tokens.
• Integrates with Terraform for IaC.
• Scripts WAF updates in CI/CD.
• Monitors via API for alerting.
• Triggers webhook notifications.
• Supports bulk operations for scaling.
• Secures with scoped API keys.

58. What is Fastly's Domain Management?

• Manages secure domain registration.
• Provides WHOIS privacy.
• Integrates with DNS management.
• Supports automated transfers.
• Monitors domain threats.
• Automates renewals for compliance.
• Enables DevOps domain automation.

59. Why use Fastly DNS?

Fastly DNS resolves queries with speed, DDoS protection, and automation for DevOps networks.

60. When enable Under Attack?

• Mitigating DDoS attacks dynamically.
• Responding to real-time threats.
• Implementing JS challenges.
• Protecting CI/CD deployments.
• Safeguarding high-traffic events.
• Ensuring security compliance.
• Blocking malicious traffic.

Learn how DevOps FAQs address attack mitigation.

61. What is Fastly Access?

• Zero Trust for secure app access.
• Integrates with SSO providers.
• Enforces least privilege policies.
• Logs access for auditing.
• Scales for enterprise users.
• Replaces VPN for remote work.
• Verifies identities in real-time.

62. Why use Fastly Gateway?

Gateway filters DNS/HTTP traffic, blocking threats for secure DevOps network access.

63. When configure Firewall Rules?

• Controlling IP-based access.
• Blocking by country or agent.
• Filtering malicious traffic.
• Automating rules in CI/CD.
• Ensuring data law compliance.
• Responding to real-time threats.
• Managing bot traffic.

64. Where use Fastly Cache?

Fastly Cache stores static assets at edge, reducing origin load for DevOps performance.

Supports dynamic purging.

65. Who uses Fastly Analytics?

• DevOps for traffic metrics.
• Security for threat insights.
• SREs for uptime monitoring.
• Platform teams for analysis.
• Developers for optimization.
• Compliance for audit logs.
• Product for user behavior.

Explore how interview prep covers analytics.

66. Which encryption features?

TLS 1.3, custom certificates, and cipher suites for secure DevOps traffic.

67. How support GitOps?

• Uses Terraform for IaC.
• Versions configs in Git.
• Automates CI/CD deployments.
• Triggers webhooks for events.
• Secures pipeline integrations.
• Supports ArgoCD workflows.
• Scales for GitOps automation.

68. What is Fastly Shielding?

• Reduces origin server load.
• Routes traffic to parent PoP.
• Improves cache hit ratios.
• Integrates with DevOps.
• Provides real-time analytics.
• Scales for global delivery.
• Reduces latency significantly.

69. Why use Fastly Load Balancing?

Fastly Load Balancing ensures high availability with health checks and failover for DevOps.

70. When enable Bot Management?

• Detecting malicious bot traffic.
• Preventing automated abuse.
• Throttling bot requests.
• Securing CI/CD endpoints.
• Ensuring API compliance.
• Managing bot challenges.
• Blocking sophisticated bots.

71. What is Next-Gen WAF?

• Advanced WAF for threat protection.
• Uses ML for anomaly detection.
• Supports custom rules.
• Integrates with DevOps.
• Provides real-time intelligence.
• Blocks attacks at edge.
• Logs for compliance auditing.

72. Why use Fastly for SSL/TLS?

Fastly provides free SSL, automatic encryption, and custom ciphers for secure DevOps traffic.

73. When configure VCL snippets?

• Customizing request/response handling.
• Rewriting URLs for optimization.
• Redirecting traffic dynamically.
• Securing staging environments.
• Adding security headers.
• Optimizing performance.
• Ensuring regional compliance.

74. Where deploy Fastly Compute?

Fastly Compute deploys WebAssembly for serverless edge functions in DevOps.

It supports low-latency execution.

75. Who uses Fastly Images?

• Developers for image optimization.
• DevOps for asset delivery.
• Security for image scanning.
• Platform teams for CDN integration.
• Product for user experience.
• Compliance for data residency.
• Teams for asset workflows.

Explore how advanced DevOps optimizes images.

76. Which Fastly analytics?

Traffic, Security, and Real User Monitoring for DevOps insights and optimization.

77. How use Fastly API?

• Automates zone configurations with tokens.
• Integrates with Terraform for IaC.
• Scripts WAF updates in CI/CD.
• Monitors via API for alerting.
• Triggers webhook notifications.
• Supports bulk operations for scaling.
• Secures with scoped API keys.

78. What is Fastly's Domain Management?

• Manages secure domain registration.
• Provides WHOIS privacy.
• Integrates with DNS management.
• Supports automated transfers.
• Monitors domain threats.
• Automates renewals for compliance.
• Enables DevOps domain automation.

79. Why use Fastly DNS?

Fastly DNS resolves queries with speed, DDoS protection, and automation for DevOps networks.

80. When enable Under Attack?

• Mitigating DDoS attacks dynamically.
• Responding to real-time threats.
• Implementing JS challenges.
• Protecting CI/CD deployments.
• Safeguarding high-traffic events.
• Ensuring security compliance.
• Blocking malicious traffic.

81. What is Fastly Access?

• Zero Trust for secure app access.
• Integrates with SSO providers.
• Enforces least privilege policies.
• Logs access for auditing.
• Scales for enterprise users.
• Replaces VPN for remote work.
• Verifies identities in real-time.

82. Why use Fastly Gateway?

Gateway filters DNS/HTTP traffic, blocking threats for secure DevOps network access.

83. When configure Firewall Rules?

• Controlling IP-based access.
• Blocking by country or agent.
• Filtering malicious traffic.
• Automating rules in CI/CD.
• Ensuring data law compliance.
• Responding to real-time threats.
• Managing bot traffic.

84. Where use Fastly Cache?

Fastly Cache stores static assets at edge, reducing origin load for DevOps performance.

Supports dynamic purging.

85. Who uses Fastly Analytics?

• DevOps for traffic metrics.
• Security for threat insights.
• SREs for uptime monitoring.
• Platform teams for analysis.
• Developers for optimization.
• Compliance for audit logs.
• Product for user behavior.

Explore how interview prep covers analytics.

86. Which encryption features?

TLS 1.3, custom certificates, and cipher suites for secure DevOps traffic.

87. How support GitOps?

• Uses Terraform for IaC.
• Versions configs in Git.
• Automates CI/CD deployments.
• Triggers webhooks for events.
• Secures pipeline integrations.
• Supports ArgoCD workflows.
• Scales for GitOps automation.

88. What is Fastly Shielding?

• Reduces origin server load.
• Routes traffic to parent PoP.
• Improves cache hit ratios.
• Integrates with DevOps.
• Provides real-time analytics.
• Scales for global delivery.
• Reduces latency significantly.

89. Why use Fastly Load Balancing?

Fastly Load Balancing ensures high availability with health checks and failover for DevOps.

90. When enable Bot Management?

• Detecting malicious bot traffic.
• Preventing automated abuse.
• Throttling bot requests.
• Securing CI/CD endpoints.
• Ensuring API compliance.
• Managing bot challenges.
• Blocking sophisticated bots.

91. What is Next-Gen WAF?

• Advanced WAF for threat protection.
• Uses ML for anomaly detection.
• Supports custom rules.
• Integrates with DevOps.
• Provides real-time intelligence.
• Blocks attacks at edge.
• Logs for compliance auditing.

92. Why use Fastly for SSL/TLS?

Fastly provides free SSL, automatic encryption, and custom ciphers for secure DevOps traffic.

93. When configure VCL snippets?

• Customizing request/response handling.
• Rewriting URLs for optimization.
• Redirecting traffic dynamically.
• Securing staging environments.
• Adding security headers.
• Optimizing performance.
• Ensuring regional compliance.

94. Where deploy Fastly Compute?

Fastly Compute deploys WebAssembly for serverless edge functions in DevOps.

It supports low-latency execution.

95. Who uses Fastly Images?

• Developers for image optimization.
• DevOps for asset delivery.
• Security for image scanning.
• Platform teams for CDN integration.
• Product for user experience.
• Compliance for data residency.
• Teams for asset workflows.

96. Which Fastly analytics?

Traffic, Security, and Real User Monitoring for DevOps insights and optimization.

97. How use Fastly API?

• Automates zone configurations with tokens.
• Integrates with Terraform for IaC.
• Scripts WAF updates in CI/CD.
• Monitors via API for alerting.
• Triggers webhook notifications.
• Supports bulk operations for scaling.
• Secures with scoped API keys.

98. What is Fastly's Domain Management?

• Manages secure domain registration.
• Provides WHOIS privacy.
• Integrates with DNS management.
• Supports automated transfers.
• Monitors domain threats.
• Automates renewals for compliance.
• Enables DevOps domain automation.

99. Why use Fastly DNS?

Fastly DNS resolves queries with speed, DDoS protection, and automation for DevOps networks.

Learn how scenario-based DevOps uses DNS.

100. When enable Under Attack?

• Mitigating DDoS attacks dynamically.
• Responding to real-time threats.
• Implementing JS challenges.
• Protecting CI/CD deployments.
• Safeguarding high-traffic events.
• Ensuring security compliance.
• Blocking malicious traffic.

101. What is Fastly Access?

• Zero Trust for secure app access.
• Integrates with SSO providers.
• Enforces least privilege policies.
• Logs access for auditing.
• Scales for enterprise users.
• Replaces VPN for remote work.
• Verifies identities in real-time.

102. Why use Fastly Gateway?

Gateway filters DNS/HTTP traffic, blocking threats for secure DevOps network access.

103. When configure Firewall Rules?

• Controlling IP-based access.
• Blocking by country or agent.
• Filtering malicious traffic.
• Automating rules in CI/CD.
• Ensuring data law compliance.
• Responding to real-time threats.
• Managing bot traffic.