In the internet era, where people are connected to each other, web server architectures have been developed and advanced. Now, we are witnessing the advent of the complex IoT (Internet of Things) era, where not only people, but also all devices on the planet are interconnected to each other and enormous amount of interactions is required. In this paper, we propose HePA (Hexagonal Platform Architecture), a platform architecture that is extremely scalable while maintaining required performance and reflecting requirements of the complex environment. We expect the HePA to become a reference architecture in this field.