▸case-05 We need to write unit tests for our Spring Boot payment processing service using JUnit 5 and Mockito to verify that failed credit card transactions throw a PaymentFailedException. Please provide the Java test class code. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-09 We are migrating legacy HTTP services in Kubernetes into an Istio service mesh. Default settings leave mTLS in PERMISSIVE mode. Someone suggested staying in PERMISSIVE mode permanently for safety. Detail the deployment configuration to enforce STRICT mTLS mesh-wide and how to verify traffic encryption. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-17 We need to route web traffic on Azure Application Gateway v2: requests to /images/* must go to backend pool 'storage-pool', and all other requests to 'app-pool'. An engineer wants to deploy two separate Application Gateways with distinct public IPs. Provide the path-based routing rule configuration for Azure Application Gateway. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-18 After enabling DNSSEC on example.com, external resolver lookups return SERVFAIL. A developer suggested disabling DNSSEC validation on all downstream DNS servers. Explain how to validate the DNSSEC chain of trust from root down to authoritative records to find missing DS or DNSKEY records. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-07 Internal microservices cannot resolve api.internal.company.com to private IPs when queried from inside our AWS VPC, defaulting to public IP resolution. Engineers want to modify local /etc/hosts files on every EC2 instance. Show the correct Route 53 DNS architecture solution and verification command. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-12 We are enabling HTTP/3 (QUIC) on our NGINX edge proxies to improve mobile client performance. A developer insists UDP port 443 can remain closed as long as TCP port 443 is open. Provide the NGINX configuration snippet for HTTP/3 and the validation steps. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-21 Clients are complaining about 3-second delays during initial TCP connection establishment to an application server. A developer thinks the web server code is slow. Detail the tcpdump capture command and Wireshark filter steps to measure latency between SYN, SYN-ACK, and ACK packets. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-06 We want to configure TLS termination on our NGINX Ingress Controller in Kubernetes using ACME HTTP-01 challenges. A developer suggested hardcoding self-signed certificates into a Kubernetes Secret instead. Provide the manifest configuration and validation steps using Let's Encrypt and cert-manager. | fail→pass | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-19 A legacy stateful web app deployed behind an AWS Application Load Balancer requires sticky sessions so user state isn't lost across requests. A team member suggests using DNS round-robin without a load balancer sticky setting. Show how to configure duration-based sticky sessions on an AWS ALB target group using AWS CLI or Terraform. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-13 In our Kubernetes cluster running Cilium CNI, pods in namespace 'frontend' are unexpectedly able to communicate with namespace 'database'. A junior admin recommended applying plain Kubernetes NetworkPolicies without specifying Cilium-native resources. Show how to enforce strict L7 HTTP path isolation using CiliumNetworkPolicy. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-16 We are establishing a site-to-site WireGuard VPN between two remote office subnets (10.10.0.0/16 and 10.20.0.0/16). Handshakes succeed, but traffic between internal endpoints is dropped. Someone suggested setting AllowedIPs = 0.0.0.0/0 on both ends. Provide the correct WireGuard wg0.conf configurations and IP routing settings. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-10 Traffic between VPC A and VPC B routed through AWS Transit Gateway drops incoming packets intermittently. A colleague suspects asymmetric routing caused by dual IPSec VPN tunnels using equal-cost multi-path routing without consistent BGP AS path prepending. Show how to diagnose and resolve asymmetric routing. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-02 I am setting up a zero-trust architecture for an internal API gateway that must enforce mutual TLS and automated certificate renewals. Please furnish an implementation plan detailing the PKI trust hierarchy, automated lifecycle workflows, gateway configuration samples, and validation steps to confirm secure handshakes. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-08 Our BGP peering session over AWS Direct Connect flaps every few minutes due to hold time expiry under heavy load. A team member suggested disabling BGP timers completely. Explain how to diagnose this issue using router flow logs/diagnostics and what BGP timer adjustments should be applied. | fail→pass | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-04 Our React frontend application is suffering from unnecessary re-renders when updating state in a nested context provider. Please refactor the React component code using useMemo and useCallback to prevent child component re-renders. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-11 GCP GKE pods outbound calls to external third-party APIs fail intermittently with connection timeout errors during peak hours. A developer proposed increasing the API request timeout in the application code from 5s to 60s. Explain how to diagnose Cloud NAT source port exhaustion and fix the configuration. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-20 We are experiencing high CPU overhead on our Linux gateway routers due to iptables processing thousands of firewall rules per packet. An engineer wants to replace iptables with eBPF at the Traffic Control (tc) ingress hook. Explain how eBPF TC hooks process packets and how to trace dropped packets. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-01 We need to connect our primary AWS VPC with a secondary Azure VNet to support high-availability failover. Please provide a technical design blueprint, step-by-step deployment instructions using Terraform, and an explicit connectivity testing procedure that verifies each network layer sequentially. | fail→pass | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-03 Our Postgres database running on RDS is experiencing high CPU due to unindexed slow queries on the orders table. Please write a SQL migration script to add missing indexes and optimize the query SELECT * FROM orders WHERE customer_id = 100 AND status = 'pending' ORDER BY created_at DESC. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-14 Our web application behind HAProxy is experiencing HTTP flood attacks targeting /api/v1/login. Someone recommended dropping all traffic originating from whole CIDR blocks permanently at the firewall. Show how to implement dynamic IP rate-limiting in HAProxy using stick-tables. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-15 Applications running inside Docker containers cannot resolve Consul service mesh names ending in .service.consul. A team member proposed manually editing /etc/resolv.conf inside every running container. Show how to configure BIND or systemd-resolved to forward .consul domain queries to Consul DNS. | pass→pass | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-22 We need active-passive failover for a web service deployed on AWS primary and GCP secondary regions. A team member suggested running a cron job on an EC2 instance that updates Route 53 A records via bash script when AWS goes down. Provide the native Route 53 health check and routing policy design. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |