reference
Part II Runtime Map
Why this page matters
Part II gives architects the browser and network model needed to make credible decisions about rendering, performance, security, caching, and delivery.
Runtime architecture map
Decisions this part supports
| Decision | Runtime knowledge required |
|---|---|
| rendering mode | browser parsing, hydration, streaming, network waterfalls |
| performance budget | main-thread cost, layout/paint, resource prioritization |
| cache strategy | HTTP cache, CDN, revalidation, coherency |
| security boundary | same-origin policy, CORS, CSP, Trusted Types |
| delivery architecture | TLS, HTTP/2/3, CDN, edge behavior |
Review checklist
- Can you explain the browser cost behind a framework abstraction?
- Can you separate network-bound, JS-bound, and render-bound slowness?
- Can you explain cache ownership across CDN, browser, framework, and client memory?
- Can you connect security headers to frontend architecture boundaries?
Exercises
- Trace one user action from input to network to paint.
- Classify one slow route as network, JavaScript, rendering, or cache-bound.
- Identify which browser/platform constraints affect one architecture decision.
Source lens
Use this map before Part III rendering/data, Part VI performance, Part VIII security, and reference architecture reviews.