Web Scraping & Data Collection
Your crawler works on your laptop and starts returning blocks, challenges or empty shells the moment you run it at volume.
Almost every scraping block traces to one of three causes, and they need different answers. Per-address accounting is the easiest: the target counts requests per IP and refuses above a threshold, so spreading the same traffic across many addresses fixes it outright. Range rejection is the second: the target refuses hosting ranges on sight, and no quantity of datacenter addresses helps, because the property being rejected is the range rather than the address. The third is behavioral: the target is scoring your headers, your TLS fingerprint and the timing of your requests, and it will keep scoring them whatever address they arrive from.
Naming the three separately matters because buying proxies solves the first two and buying the wrong kind solves neither. Find out which one you have before you spend anything. Every verified account gets a free allocation with no card, so point your existing crawler at your real target through those addresses and read what comes back. If you get the page, datacenter is enough and the cheapest tier that keeps up is the right one. If you get a block or a challenge, that target refuses hosting ranges and residential is the product; a larger datacenter plan returns the same answer more expensively.
A spread of addresses does not raise your request rate by itself, and it is worth knowing why before you tune anything. Scrapy keys its download slots on the target domain, so `DOWNLOAD_DELAY` and `CONCURRENT_REQUESTS_PER_DOMAIN` cap the whole crawl however many exits carry it: the load the target sees is unchanged, it just arrives from more places. The setting that does change this is `CONCURRENT_REQUESTS_PER_IP`, which moves the limit onto the address and quietly disables the per-domain cap. Where the pool really shows up is the invoice: on a per-gigabyte product the bytes land in billing rather than in a log, so measure what one unit of useful work costs on a small run and multiply, rather than discovering the run rate at the end of the month.
What proxies will not fix here
Rotation does not defeat behavioral detection. If a target correlates on cookies, TLS fingerprints or request timing, changing the exit changes nothing you care about, and the fix is in your client rather than in your pool. Proxies also do not make a scrape permissible: a site's terms and the law that applies to it are unaffected by where the request came from.
Start on shared or rotating datacenter and move to residential only when a target proves it refuses hosting ranges. Dedicated Premium Datacenter is the end state for heavy sustained crawls against tolerant targets, because nothing meters the traffic and a bulk run costs the same as a small one.