What is the V8 engine?
Why Interviewers Ask This
This question tests conceptual clarity. Interviewers want to hear a precise, confident definition before moving to more complex Node.js topics. It also reveals how well you can explain technical ideas to non-experts.
Answer
V8 is an open-source, high-performance JavaScript and WebAssembly engine developed by Google, written in C++. It is used in Google Chrome and Node.js. V8 compiles JavaScript directly to native machine code using Just-In-Time (JIT) compilation — rather than interpreting it line by line — making execution dramatically faster. V8 implements the ECMAScript standard and handles memory management through its garbage collector. When Node.js was created, Ryan Dahl embedded V8 into a C++ program and added APIs for file system, networking, and other OS-level operations. V8 continuously evolves to support new ECMAScript features and optimize performance, which benefits both Chrome and Node.js users simultaneously.
Common Mistake
Don't just define the term — demonstrate that you understand when to use it and when not to. Showing awareness of trade-offs is what separates average from strong Node.js candidates.
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