This document discusses return on investment (ROI) for engineers. It defines ROI as benefits minus costs and lists revenue drivers and sinks that engineering can impact. The key to success is expanding revenue through these drivers while squeezing costs, especially development and support costs. Engineers should focus on quality, managing risks, and avoiding technical debt to reduce support needs and customer issues. Rather than focusing only on numbers, engineers should aim to increase sales, support, and goodwill while decreasing costs, upset customers, escalations, and technical debt. This helps maximize financial returns over the long run.