Namaste JavaScript — Interview Quick Notes

Ep 16: JS Engine & V8 Architecture

• JS runs everywhere because of the JavaScript Runtime Environment (JRE) = JS Engine + Web APIs + Event Loop + Queues.
• ECMAScript sets the spec; each engine (V8, SpiderMonkey, Chakra) implements it.
• Three steps inside the engine: Parsing (code → tokens → AST) → Compilation (JIT: interpreter + compiler) → Execution (Memory Heap + Call Stack).
• V8 internals: Ignition (interpreter), TurboFan (optimising compiler), Orinoco (garbage collector, Mark & Sweep).