Digital transformation never looks exactly the same from one industry to the next. A factory, a hospital, a school — each has its own headaches. Yet the same basic kit of sensors, data, AI, and apps can fix wildly different problems. In this chapter we step back to see how that happens across manufacturing, healthcare, transport, energy, and education. Then we take a deep, practical walk through one surprising example: how smart waste management uses everything from IoT to blockchain to make our bins smarter and our cities cleaner.