Jhipster is a web application scaffold that generates backend and frontend code for CRUD applications. You describe entities in JDL format among other options and Jhipster generates backend server and frontend UI for you.

Here are some of the advantages:

• Fast application code scaffold. In a short time, an application is generated. 
• Many options exist on the frontend side such as React, and Angular. Vue.js is under development.
• Also, many options exist on the backend side, such as monolithic or service-oriented architecture. 
• Backend code is generated in Java code only. There is an in-progress work for Kotlin.
• It generates automated tests of all kinds, unit, integration, performance and even e2e tests.
• The code is well organized and uses best practices. You can learn a lot from it.

On the negative side:

• Jhipster generates tons of code with many libraries that you probably do not know some of them. You can not go ahead and add your business logic and modifications without reading tutorials about these technologies.
• Somewhat overuse of component, libraries, and frameworks that make your initial greenfield project complex from day one. It is like start big, rather than start small, but that was your choice from the beginning!