Self signed certificate for mobile app and backend from same company My company's product is Android and iOS mobile app which connects to our own backend. All interactions of the mobile app are with backend developed by our own company.

In such a situation, can the backend use a self signed certificate (instead of getting a certificate from CA) and pin this self-signed certificate on mobile app to make it more secure.

Please let me know if this strategy makes sense (or we still have to get SSL cert from a CA)
Yes, this (certificate pinning) is the preferred method, since it removes the reliance on external authorities and makes man in the middle attacks even harder.

An additional step would be to obscure the pinned certificate inside the application to stop it easily being edited.