LEARNING OBJECTIVES ⌵
- Use Facebook Sharing Debugger, LinkedIn Post Inspector, and Twitter Card Validator.
- Understand social media scraper caching lifetimes (often cached for 7–30 days).
- Force cache invalidation and re-scraping via platform debugger APIs.
- Inspect raw HTML responses served to social bot user agents (
facebookexternalhit,Twitterbot,LinkedInBot).
🎬 INTERACTIVE VISUAL PIPELINE
Core Architecture Simulation
1. Input
Directives & Tags
2. Parse
Tokenizer & AST
3. Layout
Box Model & Flow
4. Render
GPU Paint & Composite
PHASE 1: INPUT & DIRECTIVES
Browser receives declarative markup stream, parsing tag tokens and initializing component state.
📖 The Social Scraper Caching Problem
When a URL is shared on Facebook, LinkedIn, or Slack for the first time, their web crawler fetches the page, parses the Open Graph meta tags, caches the image and description on their CDN, and stores the preview card for up to 30 days.
If you update your og:image or fix a typo in og:title, users will still see the old cached preview until you manually trigger a re-scrape using the Facebook Sharing Debugger ("Scrape Again" button) or LinkedIn Post Inspector.
📌 Key Takeaways
- Social networks cache Open Graph tags on their edge servers; changing HTML won't update existing cards immediately without a manual re-scrape.
- Use query string cache-busting (
og:image?v=2) or dedicated platform debuggers to invalidate stale preview cards. - --
❓ Knowledge Check
1. Which of the following is correct?
2. Which of the following is correct?