Thank you Jean-Luc, I appreciate very much you pointing me to Knuthbs paper.
I am reading it now. The Introduction is awesome:

I make mistakes. I always have, and I probably always will. But I like to
think that I learn something every time I go astray. In fact, one of my
favorite poems consists of the following lines by Piet Hein:

The road to wisdom? Well, it's plain and simple to express:
Err
and err
and err again
but less
and less
and less.

I am writing this paper on 5 May 1987, exactly ten years since I began to work
on software systems for typesetting. I have certainly learned a lot during
those ten years, judging from the number of mistakes I made; and I would like
to share what I have learned with other people who are developing software.
The best way to do this, as far as I know, is to present a list of all the
errors that were corrected in TEX while it was being developed, and to attempt
to analyze those errors.

https://yurichev.com/mirrors/knuth1989.pdf