A power profiler is an instrument that accurately measures the power that your device under test (DUT) uses real-time. This allows us to see how the changes to the hardware and firmware on our latest embedded project affect the power that our device uses. In this article I explain how I used the Nordic Semiconductor Power Profiler Kit 2 (PPK2)[1] to significantly improve the battery life of a wearable assistive technology project. The profiler also played a major role in debugging when the hardware was misbehaving. A power profiler gives an extra channel of information as to what the hardware is doing in addition to our usual debugging tools. By monitoring how the current varies in a microcontroller, security experts such as Colin O’Flynn can even extract enough information as to what the internals of the microprocessor are doing to crack the encryption of supposedly secure data[, described in his article "Side-Channel Power Analysis" (Circuit Cellar 344, March, 2019) [2].