topic 05

Browser & Frontend Runtime

Event loop, rendering pipeline, V8 internals, hydration cost.

✦ 8 units ◆ 82 lessons
Start here The event loop: one thread, three queues
1
unit 01

The event loop

One thread, two queues, one render step — and everything that happens when any of them stalls.

2
unit 02

The render pipeline

Six stages, two threads, one 16.67 ms budget — how bytes become pixels, and what breaks the budget.

3
unit 03

V8 internals

Four JIT tiers, hidden classes, inline caches, Orinoco GC, and the deopt-loop — the mechanisms that make the same JS run 100× faster or slower.

4
unit 04

Workers

Off-main-thread compute, network proxy, and shared memory — the three worker primitives and the architectural mistakes they cannot solve.

5
unit 05

React fiber reconciler

A fiber is a JS object whose linked-list tree lets React pause, resume, and prioritise rendering — and the bailout mechanism is what keeps large UIs fast.

6
unit 06

Render strategies: SSR, SSG, ISR, streaming, RSC — and the cost of hydration

SSG renders once at build; SSR per request; ISR refreshes on a schedule; streaming flushes the shell first. Hydration is the separate ~2× cost of making that HTML interactive — RSC and islands cut what needs to hydrate.

7
unit 07

Core Web Vitals: LCP, INP, and CLS

Three field metrics Google scores pages on — did it show up fast (LCP), does it respond (INP), does it stay still (CLS)?

8
unit 08

Putting it all together

Page load is a relay race through network, parse, paint, and hydration — the capstone unit traces all eight layers, names the five places production reliably dies, and gives you the three-move discipline to diagnose and fix any of them.

The summit · orbit reached

You can see the whole topic now.

Every unit, from the underground to the orbit. Browser & Frontend Runtime is one constellation in the atlas — climb another topic and watch the next one light up.

Unlocks above ↑ Frontend Architecture State shape, data fetching, monorepo boundaries, build pipelines. Back to orbit Return to the atlas See every topic as one chart