Dash by Plotly looks like a great way for a Python developer to create interactive web apps without having to learn Javascript and Front End Web development. Another great project with similar aims and scope is Jupyter Dashboards.
What are the pros and cons of each?
In particular in a multi-user deployment? I also found the Plotly documentation quite unclear on what exactly is Open Source and whether the data gets uploaded to them or if the plotting can be done offline? There are clearly two modes for the underlying Plotly library but what mode does Dash operate in?