The concept of a "day of deluge" refers to the maximum load that an organization's software systems experience, often coinciding with significant events or peak usage periods. This phenomenon can be caused by various factors such as natural disasters, holidays, or widespread adoption of remote work due to pandemics. The author, who worked at a financial services company, experienced literal catastrophes during hurricanes like Sandy and Katrina, while others face more predictable but still overwhelming loads on their systems. To address this issue, developers and architects must consider techniques such as scaling up hardware, scaling out hardware, statelessness, minimizing state, caching, queuing, microservices, autoscaling, and distributed data types like conflict-free replicated data types (CRDTs). These strategies can help organizations achieve near-linear scalability, reducing the impact of diminishing returns and plateaus.