salamu alaykom,
i'm python expert, i already worked on two big projects before related to billing and accounting, with modern designs and functionalities, these softwares allow you to generate bills, save receipts, generate invoices, show dashboards with graphs and kpis, extract/load data from excel /csv files, and so many other functionalities
i can clone the whole software and provide you with executable and code in python, i'm looking forward to discuss with you in more details this project
cordially.