B2B business - serving different types of businesses

We formed a business-to-business (B2B) Software-as-a-Service (SaaS) company, that serves a perfectly halal purpose (protect companies and the wider society from fraud), this business naturally can serve a relatively wide range of services, especially financial institutions.

Question is, what is Islam opinion in serving the following types of businesses:

  • Companies that have mixed activities (e.g. conventional banks, they offer useful services such as keeping people’s money safe, but still their business model is mainly based on earning interests) or insurance businesses who have conventional and Islamic/cooperative or non-haram options.
  • Businesses with mostly haram activities (purely conventional insurance, or companies who offer loans to help with financial inclusion).
  • Purely haram businesses, like gambling, adult content and loan sharks.

Do we have an obligation to check or decide to serve / not serve these businesses based on their activities, and to what extent? and how do we handle this? do we document it and make it clear to any potential investors? and in what form? and would the answer differ based on the type of business from the above categories?

And would things be different if a reseller sells our product (we are not directly involved in the sale decision? but we still need to support if the sale happens).

Would it be different if our product was self-serve (someone can input their credit card and buy it online without our involvement)?

Many thanks

Hi everyone!

Any opinions here?

Would really appreciate the response.