| 1 | What is an APM (Application Performance Monitoring) tool, and what capabilities does it typically add beyond basic logging? Node.js › Logging & Monitoring | Node.js | Logging & Monitoring | Intermediate |
| 2 | Why is structured (JSON) logging generally preferred over plain-text console.log() statements in a production Node.js application? Node.js › Logging & Monitoring | Node.js | Logging & Monitoring | Beginner |
| 3 | What is log level (debug, info, warn, error), and how do you configure a logger like Pino or Winston to filter output by level per environment? Node.js › Logging & Monitoring | Node.js | Logging & Monitoring | Intermediate |
| 4 | How would you implement request correlation IDs to trace a single request's logs across multiple log lines and services? Node.js › Logging & Monitoring | Node.js | Logging & Monitoring | Intermediate |
| 5 | How would you implement distributed tracing across multiple Node.js microservices using OpenTelemetry? Node.js › Logging & Monitoring | Node.js | Logging & Monitoring | Advanced |
| 6 | What is the risk of exposing a raw error's stack trace in an API response, and how do you prevent it while still logging full details server-side? Node.js › Error Handling | Node.js | Error Handling | Intermediate |
| 7 | What is the DEBUG environment variable convention (popularized by the 'debug' npm package), and how does it let you enable verbose logging selectively? Node.js › Debugging & Diagnostics | Node.js | Debugging & Diagnostics | Intermediate |
| 8 | What is the risk of accidentally logging or exposing environment variables that contain secrets, and how do you prevent it? Node.js › Environment Variables & Configuration | Node.js | Environment Variables & Configuration | Intermediate |
| 9 | What is monkey-patching in the context of Node.js APM (Application Performance Monitoring) tools, and what are its risks? Node.js › Advanced Node.js | Node.js | Advanced Node.js | Advanced |
| 10 | What is observability (as distinct from traditional monitoring), and what are its three commonly cited pillars? Node.js › Cloud & DevOps | Node.js | Cloud & DevOps | Advanced |
| 11 | How would you implement a request-logging middleware in Express that captures method, path, status code, and response time for every request? Node.js › Express & Middleware | Node.js | Express & Middleware | Advanced |
| 12 | What does PM2's built-in monitoring dashboard (pm2 monit, or PM2 Plus) show, and what metrics are most useful for production operations? Node.js › Deployment & Process Managers (PM2) | Node.js | Deployment & Process Managers (PM2) | Advanced |
| 13 | How does dotnet-counters provide live performance monitoring, and what key metrics does it expose by default? .NET › Diagnostics & Performance | .NET | Diagnostics & Performance | Intermediate |
| 14 | What logging and observability practices suit a MAUI app? .NET MAUI › Best Practices & Architecture | .NET MAUI | Best Practices & Architecture | Advanced |
| 15 | What logging and observability practices suit a MAUI app? .NET MAUI › Best Practices & Architecture | .NET MAUI | Best Practices & Architecture | Advanced |
| 16 | What problem does PM2 solve for running a Node.js application in production, beyond just executing 'node server.js'? Node.js › Deployment & Process Managers (PM2) | Node.js | Deployment & Process Managers (PM2) | Beginner |
| 17 | What is the difference between fs.appendFile() and opening a file with the 'a' flag and writing to it manually? Node.js › File System & File Processing | Node.js | File System & File Processing | Intermediate |
| 18 | What is process.memoryUsage(), and how would you use it to monitor a Node.js application's memory consumption? Node.js › Global Objects & the process Object | Node.js | Global Objects & the process Object | Intermediate |
| 19 | What is the AsyncLocalStorage API, and what problem does it solve for tracking context across asynchronous calls? Node.js › Advanced Node.js | Node.js | Advanced Node.js | Advanced |
| 20 | What is the node:diagnostics_channel module, and how does it differ from simply emitting a custom event? Node.js › Advanced Node.js | Node.js | Advanced Node.js | Advanced |
| 21 | What is a dead-letter queue (DLQ), and how should a Node.js job-processing system use one? Node.js › Background Jobs & Queues | Node.js | Background Jobs & Queues | Advanced |
| 22 | What is a canary release, and how does it reduce the blast radius of a risky Node.js deployment? Node.js › Cloud & DevOps | Node.js | Cloud & DevOps | Advanced |
| 23 | What is error wrapping (or error chaining), and how does the Error class's 'cause' property support it in modern Node.js? Node.js › Error Handling | Node.js | Error Handling | Advanced |
| 24 | How would you implement automatic error reporting to a service like Sentry in a Node.js application, and what data should be scrubbed before sending? Node.js › Error Handling | Node.js | Error Handling | Advanced |
| 25 | How would you use async_hooks (the lower-level predecessor to AsyncLocalStorage) to trace the lifecycle of asynchronous resources in Node.js? Node.js › Event Loop & Non-blocking IO | Node.js | Event Loop & Non-blocking IO | Advanced |
| 26 | How would you implement a middleware that adds a correlation/request ID to every incoming request for tracing purposes across a distributed system? Node.js › Express & Middleware | Node.js | Express & Middleware | Advanced |
| 27 | How does PM2's built-in log management work, and how would you configure log rotation to prevent log files from growing unbounded? Node.js › Deployment & Process Managers (PM2) | Node.js | Deployment & Process Managers (PM2) | Advanced |
| 28 | How would you implement a dead-letter exchange in RabbitMQ to handle messages that repeatedly fail processing? Node.js › Message Queues (RabbitMQ & Kafka) | Node.js | Message Queues (RabbitMQ & Kafka) | Advanced |