Close the gap between the stairs and the wall

"Favorite pieces" because they are labor-intensive to adjust, right? Well, now at least I know what I have to take care of. Thanks

There are also corresponding parts at the hardware store, but I actually still see the stair builder as responsible here. For me, that is part of a professional installation.

Fundamental question: Why is the cheek not directly against the wall? Why is there a recess?

Solution: Possibly leave it as a "shadow gap" and only paint the visible lower strip (concrete?) in wall or stair color (definitely tricky). This way, different widths are less noticeable (to the human eye). Cleaning would also be a challenge.

Favorite parts of the carpenters because they can hide everything behind moldings When someone announces moldings everywhere, I think my part.

Did you have the staircase or plastering done by an external company? With us, it is such that we have the plastering done by a separate company, but the staircase is installed by the general contractor (soundproof staircase, therefore with a gap to the wall), and only afterwards plastered. In our case, we have to take care of concealing the gap ourselves. Maybe it is the same for you?