In modern site reliability engineering (SRE) practices, incident postmortems are a cornerstone for fostering a culture of continuous improvement by dissecting failures to gain insights into why they occurred, how they impacted operations, and how to prevent them in the future. Effective incident postmortems involve systematic management and response, including identifying contributing factors and root causes through observability software, developing actionable insights, and documenting findings to share with the broader team. Observability software shapes effective postmortem practices by providing comprehensive data collection, real-time analysis, and historical context, enabling teams to conduct thorough, insightful postmortems that go beyond immediate issue resolution to foster continuous improvement in technology operations.