A Terrible, Horrible, No-Good, Very Bad Day at Slack On May 12, 2020, Slack had our first significant outage in a long time. This is a detailed look into the technical issues that caused it. This story describes the technical details of the problems that caused the Slack downtime on May 12th, 2020. To learn more about the process behind incident response for same outage, read Ryan Katkov’s post, “