Web Browser
Rendering, CORS, service workers, storage, security
Egg
Fundamentals
Hatchling
Intermediate
Browser Storage Mechanisms
Cookies, localStorage, sessionStorage, IndexedDB, Cache API â each exists for a reason. Senior engineers choose based on constraints, not convenience.
Browser Observer APIs
IntersectionObserver, MutationObserver, ResizeObserver, PerformanceObserver â four APIs that replace polling with efficient, browser-native observation patterns.
Script Loading & Page Lifecycle Events
How and when scripts load determines your page's interactivity time. Understanding async, defer, DOMContentLoaded, and the load event sequence is fundamental to frontend performance.
How the Web Works: HTTP, REST & APIs
From URL to pixels â understanding DNS resolution, TCP/TLS handshakes, HTTP methods, REST conventions, and request/response headers is foundational knowledge every senior engineer must articulate.
Dinosaur
Advanced
The Critical Rendering Path
Every pixel on screen is the result of a pipeline. Senior engineers who understand this pipeline don't guess at performance â they engineer it.
SSR vs CSR vs Universal Rendering
The rendering strategy you choose defines your app's performance ceiling, SEO story, and infrastructure complexity. This isn't a syntax decision â it's an architecture decision.
DOM Performance & Why DOM Manipulation is Costly
The DOM is the most expensive API in the browser. Understanding why â and the mechanics of reflow and repaint â is fundamental to frontend performance.
Web Workers & Service Workers
JavaScript is single-threaded â until it isn't. Workers let you run code off the main thread, and Service Workers give you control over the network layer.
Browser Networking & Resource Loading
HTTP/2, HTTP/3, resource hints, preload, prefetch â the network layer is where performance is won or lost. Architects who control the network control the user experience.
Browser Security Model
Same-origin policy, CORS, CSP, XSS, CSRF â the browser's security model is the foundation every web application is built on. Ignorance here means vulnerabilities.
CORS Deep Dive
CORS isn't a security feature you bolt on â it's the browser's enforcement of the same-origin policy for cross-origin requests. Understanding preflight, credentials, and header negotiation prevents the most common deployment bugs.
Apex
Architect