Hi Illia. I liked your article.
Having the business requirement separate from the UI is a good idea, especially if you consider that UIs may evolve at a different pace than the business requirements. It also decreases the risk of accidentally breaking business logic when e.g. only a layout needs to be changed.
I also find it very helpful to write a test to reproduce a bug I have found, before fixing it (just did that recently). That way, I am not only sure that I fixed the bug now, but also I avoid that somebody runs into it again in the future.