With an accelerated growth of connected embedded devices and wider accessibility of hardware, Mongoose OS fills a noticeable gap for embedded software developers: the gap between Arduino firmware suitable for prototyping and bare-metal microcontrollers' native SDKs. Mongoose OS is a microcontroller operating system that comes with a set of libraries and a development framework to support typical Internet of Things (IoT) applications with connectivity to generic MQTT servers and popular IoT cloud platforms such as Google Cloud IoT Core and AWS IoT by default. In fact, Google recommends a Mongoose starter kit for its Cloud IoT Core. We’ve had a seamless experience using Mongoose OS in our embedded projects building connected workspaces. We especially liked its built-in security at the individual device level and OTA firmware updates, among other features. At the time of writing, only a limited number of microcontrollers and boards are supported with more popular ARM-based microcontrollers still under development.