React Native JSI Deep Dive — Part 2: The Bridge is Dead, Long Live JSI

"There is no doubt that the grail of efficiency leads to abuse. Programmers waste enormous amounts of time thinking about, or worrying about, the speed of noncritical parts of their programs. We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil." — Donald Knuth, Structured Programming with go to Statements , 1974 Excerpt: Every React Native native module call used to pass through a single chokepoint: the Bridge. It serialized every value to JSON, batched every call into an async queue, and made it impossible to build anything that needed to respond in under 16 milliseconds. JSI replaced it with something deceptively simple — a direct C++ function pointer. No serialization. No queue. No bridge. This post traces a native module call through both architectures so you can see exactly what changed and why it matters. Series: React Native JSI Deep Dive (12 parts — series in progress) Part 1: The Runtime You Never See | Part 2: T