What is a SEV1 incident? Understanding critical impact and how to respond

A SEV1 incident is a critical issue with high impact that must be addressed immediately. These incidents can seriously impact businesses, leading to lost revenue, unhappy customers, and operational disruptions. There are four different levels of disaster severity pertaining to an incident, ranging from Severity 4 (SEV4) to Severity 1 (SEV1), with the latter being the most severe. Key criteria for identifying a SEV1 incident include complete system outages, inability to serve customers, data loss, and high impact on business operations. When a SEV1 incident occurs, it's all-hands-on-deck, involving roles such as Incident Commander, SRE/DevOps/other specialist teams, and engineering/IT teams. Effective communication channels include instant messaging platforms, incident management platforms, video calls, email, and phone. Preventing SEV1 incidents involves proactive monitoring and maintenance, regular incident drills, and post-incident reviews. Proactive measures include continuous monitoring, automated testing, load balancing, regular software updates, and capacity planning. Regular incident drills help identify gaps in existing response plans and build team cohesion. Post-mortem reviews should focus on a blameless culture, promoting accountability and encouraging open dialogue. Post-incident best practices include conducting blameless post-mortems, effective documentation and learning from each SEV1 incident, and regular review of past incidents to reinforce lessons learned and maintain a focus on proactive incident management.