I'm on the cusp of launching an interior design software I have built with my partner (she's the interior designer, I'm the coder).

https://inspec.design

My read of the industry in terms of software is that it's split into 3 groups:

1. Interior visualisation (basically 3D renders) which largely target the what-if amateur market

2. Big, clunky and old software tools for professional interior designers working on huge projects, which works well but has that universal sort of mild dislike to strong disdain depending on the person

3. New players who want to replace the old clunky software

Seeing this, we decided not to try to overthrow the old all-powerful project management solution, but rather to replace a single process in the interior design workflow. And of course to do it very well.

Working with a partner has never been a problem, don't worry.