There is another development option called runtime transpiler. In this case, we start off by writing scripts in ECMAScript 6+ using Typescript or CoffeeScript and then Deploy the scripts to the Server. When a Request comes to the Server, it simply serves ECMAScript 6+ code without Transpiling to the Browser. Then, the browser Transpiles the scripts to ECMAScript 5 using a runtime transpiler to execute it in the client side. This type of option is not good for production applications as it puts extra load on the browser.