How do I crawl many domains without maintaining servers?

If you want to crawl many domains without running your own servers, the best approach is usually to use a serverless / managed crawling setup or a distributed scraping API. The right choice depends on scale, frequency, and how “browser-heavy” the sites are.

Good options

1) Use a managed crawling platform

These services handle scheduling, proxies, retries, rendering, and storage for you.

Common patterns:

• Submit a list of URLs/domains
• They crawl pages, follow links, extract data
• You pull results via API or export

Examples of the type of tools to look for:

• Apify
• Zyte
• Bright Data Web Unlocker / Scraping Browser
• Diffbot
• Common Crawl if you only need existing web data

Best when:

• You need scale
• You don’t want ops
• You’re okay paying for convenience

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2) Use serverless functions + queue/storage

If you want more control but still no servers:

• Use AWS Lambda, Cloud Run, Azure Functions, or Vercel/Cloudflare Workers for lightweight fetching
• Use a queue like SQS / PubSub / Redis Queue / Cloud Tasks
• Store results in S3 / GCS / Blob Storage / database
• Schedule with cron or managed schedulers

Typical architecture:

1. Seed domain list in storage
2. Queue crawl jobs
3. Serverless worker fetches a page
4. Extract links/content
5. Enqueue discovered URLs
6. Deduplicate and limit by domain rules

Best when:

• Pages are mostly static
• You want custom logic
• You’re comfortable building the pipeline

Caution:

• Pure serverless is awkward for long crawls, heavy crawling, or headless browser use
• Execution time limits can bite you

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3) Use a scraping browser / browserless API for JS-heavy sites

If sites need JavaScript rendering, use a hosted browser service rather than running Puppeteer yourself.

Look for:

• Browserless
• Zyte Browser
• Playwright/Puppeteer hosted services

You send a URL, they return rendered HTML or screenshots.

Best when:

• The sites are dynamic
• You need login/session handling
• You don’t want to manage Chromium infrastructure

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4) Use existing web datasets when possible

If you only need broad crawl data, consider:

• Common Crawl
• Search engine indexes / APIs
• Public data dumps

Best when:

• Freshness is less critical
• You need many domains but not real-time crawling

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Practical architecture for many domains

A simple low-maintenance pattern:

• Input: list of root domains
• Frontier: managed queue
• Workers: serverless fetchers or managed crawl jobs
• Dedup: hash normalized URLs
• Politeness: per-domain rate limits and robots.txt awareness
• Storage: object storage + search index or database
• Monitoring: alerts on failures, crawl depth, latency

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Key things to handle

To crawl responsibly and reliably:

• Respect robots.txt
• Add rate limits per domain
• Identify your crawler with a clear User-Agent
• Deduplicate URLs
• Normalize URLs to avoid loops
• Handle redirects, retries, and timeouts
• Separate static fetches from JS-rendered fetches

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My recommendation

If you want the fastest path with minimal ops:

• Use a managed crawling service if budget allows
• Use serverless + queue if you want custom control and low maintenance
• Use a hosted browser API for JavaScript-heavy websites

If you tell me:

1. how many domains/pages,
2. whether pages are static or JS-heavy,
3. how fresh the data needs to be,
4. your cloud preference,

…I can suggest a concrete stack and architecture.