Limited-inventory drops are a magnet for automation. A scalping bot can fill a cart and reach checkout in well under a second, far faster than any human, and it can do this hundreds of times in parallel from rotating IP addresses.
Why rate limiting alone doesn’t catch it
Traditional rate limiting looks at requests per IP. Bots have moved past that by:
- Rotating through residential proxy pools so no single IP looks abusive
- Randomizing request timing to avoid obvious bursts
- Replaying realistic-looking headers and user agents
None of that changes what happens inside the browser. A scripted checkout still moves the mouse (or doesn’t), fills forms too fast or not at all, and interacts with the page in ways that are statistically distinct from a human trying to buy a hoodie.
What actually works
Behavioral signals like mouse movement, click timing, and form-fill cadence, combined with environment checks such as headless browser detection, automation framework fingerprints, and WebDriver flags, catch what IP-based rules miss. When those signals are scored in real time, the checkout can be blocked or challenged before the order completes instead of after a chargeback shows up.
That’s the model Skyfense uses: score every session invisibly, and only act on the ones that look automated.