1. Subnetting intermediate

    A platform's cloud subnets are running out of addresses because container workloads consume one IP per pod. What happens as exhaustion approaches, and what are the options?

    2 min answer subnettingip-exhaustioncontainerscni
  2. Subnetting intermediate

    Pods have stopped scheduling on a cluster that has plenty of free CPU and memory. What do you check?

    2 min answer kubernetesip-exhaustionsubnettingcapacity
  3. TCP/IP intermediate

    An internal API is fast in isolation but a page that uses it takes 2 seconds for users in Asia while taking 200 ms in the origin region. The backend is equally fast for both. Diagnose and fix.

    2 min answer latencyround-tripstcpphysics
  4. TLS & Certificates intermediate

    A partner reports your API fails from their servers with a certificate error. It works in every browser you try and from your laptop. Diagnose and prevent.

    1 min answer tlschainincidentmonitoring
  5. TLS & Certificates intermediate

    A production outage was caused by an expired internal certificate. Nobody was tracking it. Design the fix.

    2 min answer tlsoperationsautomation
  6. TLS & Certificates intermediate

    An internal service-to-service certificate expires at 02:00 on a Sunday. What is the impact and what should have prevented it?

    2 min answer tlsautomationmonitoringoutage
  7. TLS & Certificates intermediate

    Ballot SC-081v3 cut the maximum public TLS certificate lifetime to 200 days from 15 March 2026, with 100 days from March 2027 and 47 days from March 2029. A team currently renews its 400 public certificates by quarterly ticket. What does the shorter ceiling buy, and what is the bill?

    2 min answer tlscertificatesacmeautomation
  8. TLS & Certificates intermediate

    Where should TLS terminate in a platform serving customer traffic, and what changes when a compliance requirement demands encryption in transit inside the network?

    2 min answer hasuratlsmtlsservice-mesh
  9. VPC Design intermediate

    You are designing the network for a platform expected to run for a decade, spanning multiple regions, with acquisitions likely. What do you decide on day one and why?

    2 min answer vpccidrtransit-gatewayplanning
  10. WebSockets & Realtime intermediate Multiple choice

    A collaborative editor needs to push document changes to connected clients with minimal latency. Which transport should it use, and what does the choice imply for infrastructure?

    2 min answer websocketssserealtimestateful-tier