Design a Web Crawler: FAANG Interview Question
Web crawlers are essential for AI models, requiring strategic, polite, and efficient systems to navigate and prioritize billions of web pages without overwhelming websites or duplicating content.
MAIN POINTS FROM TRANSCRIPT
- Web crawlers start with seed URLs, downloading pages, extracting links, and following them to scale to billions of pages.
- Effective crawlers must be distributed, polite, and prioritize important pages to avoid overwhelming websites.
- Crawlers use hashing to manage URL queues by host, ensuring polite access to websites.
- Prioritization and redundancy management are crucial, using factors like page popularity and content duplication detection.
TAKEAWAYS
- Crawlers must balance speed and politeness, avoiding overwhelming individual websites.
- Strategic crawling involves prioritizing high-value pages and managing millions of URLs efficiently.
- Advanced prioritization models, sometimes using machine learning, help decide which pages to crawl first.
- Redundancy is managed by systems that prevent crawling duplicate URLs and detect mirrored content.