As an interviewer, I think that certs are only useful if you take the test with a different company than you studied with. So I don’t think I’d care if you have a coursera cert, because I’d assume it just meant you finished the course that you paid for.
It’s worth noting that some coursera courses are created and maintained by actually accredited institutions, and some courses qualify as college credit with ACE accreditation. Also, many tech certifications host their courses on coursera too, like microsoft has official azure cert courses on there.
That doesn’t necessarily mean anything for any given random cert, though, because that means that the entire site is a pretty big grab bag in terms of the usefulness of their certs.
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.