We used React to render all the components. We wrapped fonts, icons, images and other componets with Webpack.
We made a Drag and Drop feature to drag cards within the tasks boards, the libary we used to do that was ReactDnD.
All the styles were done with Sass.
We used NodeJS for the backend and MongoDB for the database.
As the tool can be used for different users at the same time we implemented real time changes using Websockets.