What to use for an interactive website builder?

Question

Web development

The task is as follows - the site should have a visual designer of the elements of the engineering system. That is, the user drags elements from the "palette" of ready-made blocks, puts them in a certain order in rad, indicates the input and desired output parameters, presses the button, and the system calculates the technical characteristics of the finished structure - takes data from the database for each used node, calculates the best option designs, shows which specific elements to use, prints out a technical sheet and a sketch (a sketch is, in fact, what the user has drawn in the constructor). The database of components will be filled by developers and engineers, they (engineers) will also write calculation algorithms, I hope there will be no problems with this. In addition to this functionality, you will probably only need registration,
Actually the question is what technologies are better to use for this, perhaps there are ready-made libraries for such graphic designers? How high can the complexity of such a development be?
UPD: Thank you all for your advice and help!

Answer 1

ready-made frameworks-templates make for typical-standard tasks
in your case it’s easier to write
a simple task from scratch