 WeChat Pay is already a normal part of our life in China. If you do not have WeChat Pay, you cannot do anything. We are doing our best to satisfy the rapidly growing business needs. We have helped more than one billion users and several million merchants. There are so many kinds of services that need to be managed, so we developed an API gateway. The API gateway manages all the APIs and provides authentication, identification, service quality and monitoring. One of the challenges we face is that our business environment requires the mixed deployment of Windows and Linux. Therefore, we need to use .NET Core to bring order to the entire ecosystem of the company. We think that open source suits the development of our system better since it is modularized and more transparent. .NET Core is a modern platform specifically designed for microservices. In the development process, we always use Visual Studio 2017. We develop on Windows 10, then we can deploy directly to Linux. We developers love our company because at 10 cent, we are free to utilize our skills. If you like Java or .NET or C++, you can use whatever you want. Developers can reach their full potential in this environment. Our boss once said, create masterpieces. Through open source, I can collaborate with developers from around the world.