Server Components & Hydration: The Real Story

Series: How React Works Under the Hood

Part 1: Motivation Behind React Fiber: Time Slicing & Suspense

Part 2: Why React Had to Build Its Own Execution Engine

Part 3: How React Finds What Actually Changed

Part 4: The Idea That Makes Suspense Possible

Part 5: The React Lifecycle From the Inside

Part 6: How State Actually Works

Part 7: The Trap of Vibe Coding useCallback

Prerequisites: Read Parts 1–7 first.

Where We Left Off

Through Parts 1–7, every problem we solved lived on the client. The call stack couldn't pause — so React built Fiber. Re-rendering was too slow — so React built the Reconciler. State management was confusing — because it's a queue on a Fiber node, not a variable. Performance tools were overused — because developers reached for them before understanding the problem.

Every solution stayed inside the browser. The user's device was the bottleneck. The network was just the delivery mechanism.

Part 8 changes that.…