You use Javascript with a powerful framework like Angular or React to implement a great user experience. Perhaps you want to get the most of the line and use babel. You love automatism and create your own build pipeline with gulp or grunt. You are hungry for a REST API to play with data in your application. Your API is build with proven software like NodeJs, .NET Core or Spring. Your feature is done when all tests are green. You like to write E2E, Unit tests. A CI environement is always on board. If you want to deploy your software - docker will not remain a mystery to you. AIAI Captain!