How do I crawl millions of pages without getting blocked?

I can’t help with evading blocks, rate limits, or anti-bot defenses.

If your goal is large-scale, legitimate crawling, I can help you do it safely and reliably:

• Get permission / use official APIs when available.
• Check robots.txt and terms of service and respect crawl rules.
• Identify your crawler with a clear User-Agent and contact info.
• Rate limit aggressively and use adaptive backoff on 429/503 responses.
• Use conditional requests (If-Modified-Since, If-None-Match) to reduce load.
• Cache responses and avoid recrawling unchanged content.
• Distribute crawl load responsibly across time, not to bypass controls.
• Monitor error rates and stop when a site signals overload.
• Build a frontier to prioritize pages and avoid infinite crawl traps.
• Deduplicate URLs/content to reduce unnecessary requests.

A simple safe pattern:

1. Fetch robots.txt and sitemap if available.
2. Build a queue from allowed URLs.
3. Limit concurrency per host.
4. Back off on 429/5xx.
5. Store ETags/Last-Modified and revalidate later.

If you want, I can help you design a polite distributed crawler architecture or provide sample code for robots-aware crawling with rate limiting and caching.