Problem Context

We have a set of excel reports which are generated from an excel input provided by the user and then fed into SAS for further transformation. SAS pulls data from Teradata database and then there is a lot of manipulation that happens with the input data & data pulled from Teradata. Finally, a dataset is generated which can either be sent to the client as a report, or be used for populating Tableau dashboard. Also the database is being migrated from Teradata to Google Cloud (Big Query EDW) as the Teradata pulls from SAS used to take almost 6-7 hours

Problem Statement Now we need to automate this whole process, by creating front end for the user to upload the input files and from there on the process should trigger and in the end the user should receive the excel file or Tableau dashboard as an attachment in a mail.

1. Can you suggest what technologies should be used in the front end & middle tier to make this process feasible is least possible time with google cloud platform as the backend?
2. Can an R shiny front end be a solution given that we need to communicate with a Google Cloud backend ?
3. I have got suggestion from people that Django will be a good framework to accomplish this task. What are your views on this ?