Energy efficiency is at the heart of building truly sustainable digital infrastructure. While design plays an important role, the way a data center is operated day to day—how energy is monitored, managed, and optimized—has an even greater long-term impact. Improving energy efficiency won’t solve every challenge facing data center owners and operators, but it can address many of them—reducing environmental impact, lowering operating costs, and strengthening operational resilience. Small improvements in how facilities are measured, managed, and optimized can translate into significant savings at scale. This topic will look at practical steps data centers can take to improve their energy efficiency from lessons learned in the field.