Around 3:40 PM Eastern Time, Greenhouse became aware of backed-up queues related to our job board APIs. We identified the incident at 4:04 as a Denial of Service attack affecting one of our customers which was being passed through to our job board APIs. At 4:12 PM, we blocked the IP addresses that were causing the degraded performance and the job board system began its recovery.

This incident would have appeared as slow processing on candidate applications and job boards between 3:17 PM and 4:12 PM Eastern Time. Greenhouse will be exploring ways to mitigate attacks of these time going forward.