Woke up to a dead campaign because my residential proxy pool was crawling at like 2000ms average response time lost a whole day of scaling and it's the provider I've been using for months their dashboard showed all green but the actual requests were timing out mid-session My bad for trusting their built-in speed test it's just pinging their own servers doesn't mean squat for real world use you need to test with your actual tool puppeteer selenium whatever and measure from session start to first meaningful action I scripted a quick check that hits a target site three times and logs the real completion time not some vanity metric Creative testing is more important than targeting but if your proxies are junk you can't even get the creatives in front of anyone anyone else have a solid method beyond just pinging google.com