Conceptual
Explain how things work â deep understanding questions
Egg
Fundamentals
Hatchling
Intermediate
Explain the Virtual DOM
The virtual DOM is React's most misunderstood feature. Here's how to explain it like a senior engineer â focusing on why, not what.
Explain Closures and this
Two of the most-asked JavaScript concepts. Your explanation reveals whether you understand the language's execution model or just memorized definitions.
Common JavaScript Memory Leaks
Memory leaks in SPAs are silent performance killers. This question tests whether you've debugged real production issues or only worked on greenfield code.
Why is DOM Manipulation Costly?
This question tests whether you understand the browser's rendering architecture or just parrot 'the DOM is slow.'
CSS Specificity & Architecture
CSS specificity is a scoring system, not magic. Understanding it â plus modern CSS architecture â separates engineers who fight CSS from those who wield it.
CSS Specificity and Layout Explained
Specificity wars sink large codebases. Your answer reveals whether you fight CSS or architect it.
Dinosaur
Advanced
How Does the JavaScript Event Loop Work?
The question that separates developers who write async code from developers who understand async code. Your answer reveals your mental model.
Explain the Critical Rendering Path
This question tests whether you understand how browsers actually render pages â or if you just know that 'HTML becomes a page somehow.'
How Would You Optimize a Slow Web App?
This open-ended question tests your diagnostic framework, not just your knowledge of techniques. Senior engineers have a systematic approach, not a bag of tricks.
TypeScript Generics Explained
Generics separate TypeScript beginners from experts. Your answer shows whether you use the type system or fight it.
Apex
Architect