| 1 | What is snapshot testing and what's a common pitfall with it? JavaScript › Debugging, Testing & Tooling | JavaScript | Debugging, Testing & Tooling | Advanced |
| 2 | How do you pause code execution at a specific line using the browser DevTools? JavaScript › Debugging, Testing & Tooling | JavaScript | Debugging, Testing & Tooling | Beginner |
| 3 | What is console.table() useful for? JavaScript › Debugging, Testing & Tooling | JavaScript | Debugging, Testing & Tooling | Beginner |
| 4 | What is a unit test and what makes a good one? JavaScript › Debugging, Testing & Tooling | JavaScript | Debugging, Testing & Tooling | Beginner |
| 5 | How does Jest's mocking help isolate the code under test? JavaScript › Debugging, Testing & Tooling | JavaScript | Debugging, Testing & Tooling | Intermediate |
| 6 | What is code coverage and why isn't 100% coverage the same as bug-free code? JavaScript › Debugging, Testing & Tooling | JavaScript | Debugging, Testing & Tooling | Intermediate |
| 7 | How does source mapping help when debugging minified or transpiled code? JavaScript › Debugging, Testing & Tooling | JavaScript | Debugging, Testing & Tooling | Intermediate |
| 8 | How do you write an effective test for asynchronous code? JavaScript › Debugging, Testing & Tooling | JavaScript | Debugging, Testing & Tooling | Advanced |
| 9 | How does the Performance panel in DevTools help diagnose a janky UI? JavaScript › Debugging, Testing & Tooling | JavaScript | Debugging, Testing & Tooling | Advanced |
| 10 | What's the difference between end-to-end (E2E) tests and unit tests, and when do you use each? JavaScript › Debugging, Testing & Tooling | JavaScript | Debugging, Testing & Tooling | Advanced |
| 11 | What is a memory leak in JavaScript, given that it has automatic garbage collection? JavaScript › Memory Management & Garbage Collection | JavaScript | Memory Management & Garbage Collection | Beginner |
| 12 | How would you use Chrome DevTools' heap snapshot comparison to find a leak's source? JavaScript › Memory Management & Garbage Collection | JavaScript | Memory Management & Garbage Collection | Advanced |
| 13 | What is XMLHttpRequest and why would you still use it over fetch() today? JavaScript › Networking: Fetch, XHR, WebSockets & CORS | JavaScript | Networking: Fetch, XHR, WebSockets & CORS | Advanced |
| 14 | How would you use a memory profiler (or dotnet-counters / dotnet-gcdump) to diagnose excessive garbage collection pressure in a production .NET application? C# › Memory & Garbage Collection | C# | Memory & Garbage Collection | Advanced |