For the last 15 years, I have been working on medical device software. I fully understand your desire to make the world a better place based on your career choices. Every day, I am excited to go in to work for that very reason. I have had the privilege of working on NICU ventilators (think preemies born at 22 weeks), pulse oximetry, ECG devices, infusion pumps, and now ultrasound. It is fairly common in the medical device world for management to invite patients and families to visit the engineers who worked on the devices that saved lives. I particularly remember a perfect, healthy, beautiful 18-month old little girl and her parents. She had been born severely premature, and was kept alive for months in a NICU on one of our ventilators. Tears all around the room! Medical device engineers make the devices that clinicians use, and consequently have a potentially huge multiplicative impact on people's lives. My last ventilator product family has an installed base of over 200,000 units worldwide. I like to think about the transitivity of the situation: you save or improve one life. That also has a huge impact on that person's immediate family. Then, consider the secondary and tertiary impacts that emanate out to extended family, and whole communities. Moreover, medical device software is extremely challenging and interesting to work on. Tons of new stuff to learn along multiple different dimensions. It is frequently "close to the metal" programming, so you need to be in to that sort of thing to enjoy it. (A note of realism: our real goal is simply to move the probability needle on patient outcomes. But in fact, that is enough.)