▸case-01 Our production API endpoint occasionally throws an unhandled 500 internal server error during high-traffic windows. I keep guessing at possible causes like memory leaks or DB connection limits, but I want to stop shooting in the dark. Can you walk me through a disciplined, step-by-step troubleshooting workflow to reliably recreate the problem, narrow down the fault location, dig into why it happens, and confirm a fix? | fail→pass | 20,090 | 19,746 | -2% | 1 | 1 | 0% | 3,337 | 2,662 | -20% | 0 | 0 | — |
▸case-02 I'm facing a weird issue where user session state gets wiped whenever a customer refreshes the checkout page in our web app. Instead of applying random patches, please guide me through a structured debugging procedure to isolate the component at fault, perform root-cause analysis, and verify the patch. | fail→pass | 26,864 | 16,220 | -40% | 1 | 1 | 0% | 3,599 | 2,119 | -41% | 0 | 0 | — |
▸case-03 Our background job processor stalls after handling roughly 10,000 tasks, but there are no explicit error logs. I need a systematic framework to investigate this performance degradation—help me structure the process from reproducing and isolating the issue to identifying the fundamental underlying cause and testing the solution. | fail→pass | 27,267 | 21,298 | -22% | 1 | 1 | 0% | 3,478 | 2,743 | -21% | 0 | 0 | — |
▸case-04 A Kubernetes microservice pod running a Python FastAPI app enters CrashLoopBackOff every 2 hours under light load. The operations team suggested immediately increasing CPU limits and restarting pods automatically. Outline a step-by-step technical plan to systematically diagnose and resolve this issue without relying on speculative resource adjustments. | fail→pass | 22,593 | 25,983 | +15% | 1 | 1 | 0% | 3,807 | 3,658 | -4% | 0 | 0 | — |
▸case-05 In a React application, a customer profile page triggers an infinite re-render loop on render when updating cart items. Developers want to immediately add a try-catch block and debounce the effect hook as a hotfix. Detail a structured investigation workflow that prevents premature patching. | fail→pass | 20,040 | 18,133 | -10% | 1 | 1 | 0% | 3,095 | 3,391 | +10% | 0 | 0 | — |
▸case-06 A PostgreSQL database experiences intermittent transaction deadlocks during midnight bulk import runs. Engineers plan to immediately alter database isolation levels or wrap queries in retry loops. Provide a disciplined step-by-step plan to investigate and correct the transaction conflicts. | fail→pass | 23,371 | 23,572 | +1% | 1 | 1 | 0% | 2,887 | 3,411 | +18% | 0 | 0 | — |
▸case-07 An e-commerce service experiences sporadic 5-second latency spikes in its payment gateway integration during checkout. The backend lead wants to immediately rewrite the gateway HTTP client library. Formulate a multi-phase diagnostic framework to identify the defect location and root cause. | fail→fail | 19,674 | 24,663 | +25% | 1 | 1 | 0% | 3,218 | 3,287 | +2% | 0 | 0 | — |
▸case-08 A Redis-backed caching layer fails to invalidate user authorization tokens upon password reset, leaving stale tokens active. The team wants to deploy a scheduled script to flush all Redis keys hourly. Outline a methodological debugging workflow to resolve this authorization caching flaw. | fail→pass | 22,474 | 17,470 | -22% | 1 | 1 | 0% | 2,840 | 3,185 | +12% | 0 | 0 | — |
▸case-09 An iOS Swift app crashes due to out-of-memory errors after scrolling through an image feed for 15 minutes. Developers are suggesting restarting the image loader singleton on view unmount as an immediate fix. Provide a formal debugging protocol to handle this memory leak properly. | fail→pass | 23,816 | 21,637 | -9% | 1 | 1 | 0% | 3,915 | 3,924 | +0% | 0 | 0 | — |
▸case-10 A Go microservice worker pool accumulates blocked goroutines over several days, eventually causing out-of-memory panics. The team proposes doubling RAM allocated to the container. Provide a structured 4-phase debugging plan to solve the leakage. | fail→pass | 14,516 | 16,085 | +11% | 1 | 1 | 0% | 2,513 | 2,777 | +11% | 0 | 0 | — |
▸case-11 A GraphQL query for fetching user order histories triggers hundreds of duplicate SQL queries, causing high database load. A developer wants to immediately disable field nesting in the schema. Lay out a systematic problem-solving procedure to address this N+1 performance bug. | fail→pass | 14,326 | 20,235 | +41% | 1 | 1 | 0% | 2,342 | 2,824 | +21% | 0 | 0 | — |
▸case-12 An Apache Kafka consumer group enters endless rebalance loops when processing large payload batches. Operators want to randomly tweak session timeouts and heartbeat intervals until it stops. Detail a structured workflow to diagnose and resolve this consumer instability. | fail→pass | 17,254 | 27,599 | +60% | 1 | 1 | 0% | 2,947 | 3,948 | +34% | 0 | 0 | — |
▸case-13 An Electron desktop application crashes with EMFILE (too many open files) after exporting multiple PDF reports. The team suggests increasing system file limits via shell script. Provide a formal debugging workflow to address the resource leak. | pass→pass | 20,919 | 27,703 | +32% | 1 | 1 | 0% | 3,638 | 4,003 | +10% | 0 | 0 | — |
▸case-14 An Elasticsearch cluster throws bulk indexing HTTP 429 write queue rejection errors during peak log ingestion. Engineers want to immediately add nodes to the cluster. Provide a structured troubleshooting roadmap to isolate and resolve the ingestion bottleneck. | fail→fail | 23,080 | 26,507 | +15% | 1 | 1 | 0% | 2,955 | 3,685 | +25% | 0 | 0 | — |
▸case-15 A Node.js API gateway intermittently rejects valid OAuth JWT tokens with signature verification failure errors. A developer suggests wrapping JWT verification in an automated retry loop. Describe a disciplined debugging strategy to locate and fix the signature verification bug. | fail→pass | 28,151 | 21,927 | -22% | 1 | 1 | 0% | 3,222 | 3,809 | +18% | 0 | 0 | — |
▸case-16 A web application dashboard experiences noticeable UI freezing during table sorting because of DOM layout thrashing. A front-end developer wants to add CSS hardware acceleration hacks immediately. Outline a systematic debugging process to fix the layout issue. | fail→pass | 20,908 | 20,186 | -3% | 1 | 1 | 0% | 2,754 | 2,703 | -2% | 0 | 0 | — |
▸case-17 A React web app build pipeline produces inconsistent bundle hashes across CI builds despite zero code changes. The DevOps team proposes turning off hash generation. Create a step-by-step debugging workflow to resolve the non-deterministic build behavior. | fail→pass | 26,878 | 17,265 | -36% | 1 | 1 | 0% | 3,195 | 3,125 | -2% | 0 | 0 | — |
▸case-18 A native C++ network parser crashes with a segmentation fault when handling malformed packet headers. A developer wants to insert null pointer checks arbitrarily throughout the parser module. Guide the team through a structured debugging procedure. | fail→pass | 22,258 | 24,386 | +10% | 1 | 1 | 0% | 2,762 | 3,493 | +26% | 0 | 0 | — |
▸case-19 A Django web app occasionally creates duplicate user profiles when two signup requests arrive simultaneously. The team plans to add a global lock around the entire user registration view. Provide a structured debugging workflow to address the race condition correctly. | pass→pass | 23,574 | 19,942 | -15% | 1 | 1 | 0% | 2,866 | 2,884 | +1% | 0 | 0 | — |
▸case-20 An AWS Lambda function servicing user authentication times out intermittently during cold starts. The infrastructure team plans to set provisioned concurrency to maximum without investigation. Detail a structured debugging workflow to diagnose and fix the latency. | fail→pass | 26,439 | 27,222 | +3% | 1 | 1 | 0% | 3,471 | 3,737 | +8% | 0 | 0 | — |
▸case-21 We are designing a new real-time video streaming service architecture from scratch using WebRTC and microservices. Create a high-level architecture design document covering component design, media server selection, load balancing strategy, and database schema recommendations. | pass→pass | 45,441 | 37,602 | -17% | 1 | 1 | 0% | 8,235 | 6,268 | -24% | 0 | 0 | — |
▸case-22 Write a comprehensive Jest unit test suite for a newly implemented string utility library that formats currency values and sanitizes HTML inputs. The code works correctly and has no reported bugs. | pass→pass | 27,352 | 26,027 | -5% | 1 | 1 | 0% | 4,526 | 4,430 | -2% | 0 | 0 | — |
▸case-23 Author an OpenAPI 3.0 YAML specification for a user management REST API containing endpoints for listing users (GET /users) and creating users (POST /users) with JSON schemas. | pass→pass | 19,019 | 10,885 | -43% | 1 | 1 | 0% | 3,232 | 2,893 | -10% | 0 | 0 | — |