They were ripping off both their users and anyone using affiliate links (including the content creators who promoted them)
During checkout, when you clicked the “find coupon” button in honey (which it prompted you to do on screen during checkout), it would strip out any affiliate link and add their own. So if you clicked on a product from a review, they would strip out the referral link from the YouTube video or website that sent you and indicate they sent you instead and get the commission.
In addition, they were working with online retailers and basically extorting them. They said that if retailers paid them a fee, they got to pick the discount code that was used during checkout. So if there was a 20% coupon and a 5% coupon, stores could pay them to ignore the 20%.
This, in turn, was basically faking out their users, thinking they were giving them the “best deal” like they claimed to.
i second the comment that you need to consider why you want to do this. You generally need a pretty good reason to split your codebase into multiple languages.
As far as actually doing it, you have a ton of different options, some of which have been mentioned here. Some i can think of off the top of my head:
basically every approach is going to require you to come up with some sort of API that the two work together through, though, an API in the generic sense is basically a shared contract two disconnected pieces of code use to communicate.