▸case-06 We are migrating a monolith into separate microservices. A team lead suggests keeping a single central PostgreSQL database with all microservices querying the same database tables directly to avoid data replication. Evaluate this approach against microservices decomposition principles. | pass→pass | 15,452 | 14,938 | -3% | 1 | 1 | 0% | 2,443 | 2,481 | +2% | 0 | 0 | — |
▸case-05 Provide a Mermaid diagram definition showing traffic flow from Edge Gateway to Auth Service, and from Edge Gateway to Payment Service, directed top-to-bottom. | pass→pass | 2,657 | 1,927 | -27% | 1 | 1 | 0% | 366 | 324 | -11% | 0 | 0 | — |
▸case-01 We need to document our modern retail system for non-technical stakeholders to show high-level boundaries and interactions with third-party payment providers like Stripe and logistics partners like FedEx. A junior developer suggested drawing microservices and internal classes. Which level of the C4 diagram model should be created first? | pass→pass | 5,353 | 5,691 | +6% | 1 | 1 | 0% | 1,044 | 983 | -6% | 0 | 0 | — |
▸case-02 In an e-commerce platform audit, Order Service makes synchronous HTTP calls to Inventory Service, Inventory Service calls Pricing Service, and Pricing Service makes synchronous HTTP calls back to Order Service. What dependency anti-pattern exists, and how should it be resolved? | pass→pass | 11,241 | 11,589 | +3% | 1 | 1 | 0% | 1,938 | 2,006 | +4% | 0 | 0 | — |
▸case-03 We are setting up dynamic service graph generation across our distributed infrastructure without manually creating static architectural diagrams. What telemetry standard and signal type should be instrumented across microservices? | pass→pass | 9,609 | 13,953 | +45% | 1 | 1 | 0% | 1,481 | 1,785 | +21% | 0 | 0 | — |
▸case-04 In a fintech application, Service Alpha, Service Beta, and Service Gamma all execute direct synchronous database queries against a shared legacy Account master database. What system topology risk does this create during an database outage? | fail→pass | 9,278 | 11,888 | +28% | 1 | 1 | 0% | 1,470 | 1,800 | +22% | 0 | 0 | — |
▸case-07 We need to break apart a legacy mainframe core banking system into cloud-native services gradually while running both systems concurrently in production without doing a risky big-bang rewrite. What system migration pattern should be applied? | pass→pass | 12,036 | 14,348 | +19% | 1 | 1 | 0% | 1,998 | 2,198 | +10% | 0 | 0 | — |
▸case-08 During checkout in an e-commerce platform, the Order Service executes a synchronous HTTP POST call to an external Logistics Service to generate shipping labels before confirming the user's order. If Logistics Service is slow, checkout times out. What coupling model should be used instead? | pass→pass | 9,701 | 10,842 | +12% | 1 | 1 | 0% | 1,647 | 1,757 | +7% | 0 | 0 | — |
▸case-09 Write a Graphviz DOT diagram definition for a 3-stage pipeline dependency: source-fetch -> container-build -> deployment-rollout. | pass→pass | 5,583 | 5,155 | -8% | 1 | 1 | 0% | 1,027 | 986 | -4% | 0 | 0 | — |
▸case-10 In an enterprise supply chain application, 'Product' has completely different attributes and business logic in Warehousing vs Accounting. A developer wants to create one global Product class used by all services. How should domain-driven decomposition address this? | pass→pass | 14,856 | 16,433 | +11% | 1 | 1 | 0% | 1,903 | 2,218 | +17% | 0 | 0 | — |
▸case-11 Service A depends on Service B via HTTP. When Service B encounters intermittent latency spikes, Service A runs out of HTTP connection pool threads and crashes. What resiliency pattern should be added to the dependency interface? | pass→pass | 7,661 | 10,780 | +41% | 1 | 1 | 0% | 1,277 | 1,789 | +40% | 0 | 0 | — |
▸case-12 We have 15 interconnected services and need a matrix-based documentation technique to systematically track which services call which other services for impact analysis. What structural representation should be created? | pass→pass | 12,369 | 12,924 | +4% | 1 | 1 | 0% | 2,162 | 2,228 | +3% | 0 | 0 | — |
▸case-13 We want to construct a dynamic, real-time dependency map of all HTTP and gRPC service-to-service traffic in Kubernetes without modifying application code or installing custom SDKs in every application repository. What infrastructure technology enables this? | pass→fail | 12,139 | 16,249 | +34% | 1 | 1 | 0% | 1,958 | 2,029 | +4% | 0 | 0 | — |
▸case-14 Decompose a traditional 3-tier web architecture into its core structural tiers and state the primary responsibility of each tier. | pass→pass | 6,923 | 6,556 | -5% | 1 | 1 | 0% | 1,222 | 1,278 | +5% | 0 | 0 | — |
▸case-15 Service Order Processing directly calls the Twilio SDK to send SMS notifications. We want to decouple Order Processing so we can switch providers to SNS or Infobip with zero modifications to core business logic. Which design principle should be applied? | pass→pass | 6,001 | 8,313 | +39% | 1 | 1 | 0% | 1,154 | 1,501 | +30% | 0 | 0 | — |
▸case-16 An engineering group decomposed an authentication module into 8 distinct deployed services: ValidatePassword, HashPassword, GenerateJWT, VerifyJWT, RefreshToken, StoreToken, DeleteToken, and LookupUser. Evaluate this decomposition granularity. | pass→pass | 14,560 | 15,670 | +8% | 1 | 1 | 0% | 2,273 | 2,512 | +11% | 0 | 0 | — |
▸case-17 In a media streaming system, Video Metadata Service calls Recommendation Engine Service synchronously to show recommended videos. If Recommendation Engine fails, what failure handling design prevents the entire video watch page from failing? | pass→pass | 17,841 | 16,437 | -8% | 1 | 1 | 0% | 1,925 | 1,993 | +4% | 0 | 0 | — |
▸case-18 We are designing a multi-step saga for processing orders involving Payment Service, Inventory Service, and Shipping Service. Contrast event choreography versus saga orchestration for managing dependency flows across these services. | pass→pass | 15,914 | 19,271 | +21% | 1 | 1 | 0% | 2,773 | 3,416 | +23% | 0 | 0 | — |
▸case-19 A mobile iOS application and a desktop web application require vastly different response payloads from the same backend infrastructure. Instead of adding conditional logic to a single monolithic API layer, what backend architecture pattern should be implemented? | pass→pass | 7,879 | 8,817 | +12% | 1 | 1 | 0% | 1,157 | 1,338 | +16% | 0 | 0 | — |
▸case-20 In C4 architecture modeling, we have drawn the Container diagram showing Payment API, Postgres DB, and Redis Cache. Now we need to map the internal controllers, services, and repository classes inside Payment API. Which C4 level diagram should be authored? | pass→pass | 3,744 | 4,766 | +27% | 1 | 1 | 0% | 670 | 790 | +18% | 0 | 0 | — |
▸case-21 Create a Kubernetes HorizontalPodAutoscaler YAML resource for deployment `orders-api` that scales between 2 and 10 pods when CPU utilization exceeds 80%. | fail→pass | 3,883 | 4,023 | +4% | 1 | 1 | 0% | 782 | 715 | -9% | 0 | 0 | — |
▸case-22 A PostgreSQL query `SELECT * FROM audit_logs WHERE tenant_id = $1 AND log_level = 'ERROR' ORDER BY created_at DESC` is running slowly. Write the SQL CREATE INDEX DDL to optimize this query. | pass→pass | 7,846 | 8,404 | +7% | 1 | 1 | 0% | 1,175 | 1,511 | +29% | 0 | 0 | — |
▸case-23 Write a YAML configuration snippet for a GitHub Actions workflow using `actions/cache` to cache Maven dependencies in `~/.m2/repository` based on `pom.xml` hash. | pass→pass | 4,366 | 3,299 | -24% | 1 | 1 | 0% | 771 | 615 | -20% | 0 | 0 | — |