Complex Financial Calculations in Bubble

Your description and context is too vague to make a recommendation but I’ve built a SaaS app doing something along the same lines.

Math.js is one way… check out the plugins
you can do some stuff in bubble
Google sheets api is one way but it has rate limits …

I ended up using this from @AliFarahat

If you think of math.js as the police then this is like SWAT