1. Content Delivery Networks intermediate

    A social platform serves large volumes of user-generated media with an extremely skewed popularity distribution and a cost-sensitive business. How should the delivery path be designed?

    2 min answer sharechatcdnskewcost
  2. Content Delivery Networks intermediate

    You put a CDN in front of your site. Cache hit rate is 12%. Origin load is barely reduced. Why?

    2 min answer cachingcdnperformance
  3. DNS intermediate Multiple choice

    Why is DNS a poor primary mechanism for fast failover, and what should be used instead for a globally distributed service?

    2 min answer dnsfailoveranycastttl
  4. DNS intermediate

    You use DNS with a 60-second TTL for regional failover. During a test, some traffic still hit the failed region 40 minutes later. Explain.

    2 min answer dnsfailoverresilience
  5. Firewalls & Security Groups intermediate

    An auditor asks you to prove the reporting service cannot reach the payments database. What evidence would you produce, and why is a screenshot of the security group not it?

    3 min answer reachabilityauditflow-logssecurity-groups
  6. Firewalls & Security Groups intermediate

    An enterprise platform has accumulated thousands of network security rules over years, and nobody can determine whether a given rule is still needed. What is the diagnosis and what would you change?

    2 min answer network-securitysecurity-groupspolicyleast-privilege
  7. Firewalls & Security Groups intermediate

    Automated traffic is 60% of your requests, distorting analytics and consuming capacity. Where do you handle it and how?

    2 min answer cloudflarebotsedgecapacity
  8. gRPC Transport intermediate

    A file-sync company moves internal service communication from JSON over HTTP to gRPC. What improves, what gets harder, and where would you keep HTTP/JSON?

    2 min answer grpcprotobufinternal-apisstreaming
  9. gRPC Transport intermediate

    A telemetry platform must choose between HTTP/JSON and gRPC for high-volume ingestion from thousands of agents. What actually decides it?

    1 min answer grafanagrpcingestionprotocols
  10. gRPC Transport intermediate

    An organisation standardises internal service communication. What actually distinguishes gRPC from JSON over HTTP at scale, and where does each break down?

    2 min answer grpcrestprotobufstreaming
  11. HTTP/1.1, HTTP/2 & HTTP/3 intermediate

    A platform is considering moving customer traffic to HTTP/3. What does it actually improve, for whom, and what does it complicate?

    2 min answer vercelhttp3quicmobile
  12. HTTP/1.1, HTTP/2 & HTTP/3 intermediate Multiple choice

    A team upgrades to HTTP/3 and median page load time is unchanged. Was the upgrade worthless?

    2 min answer http3quictail-latencymeasurement