Designer, implementor, user, writer A Fragment by Donald Knuth dl.acm.org Thus, I came to the conclusion that the designer of a new system must not only be the implementor and the first large-scale user; the designer should also write the first user manual. The separation of any of these four components would have hurt TeX significantly. If I had not participated fully in all these activities, literally hundreds of improvements would never have been made, because I would never have thought of them or perceived why they were important. Eating your own dog food making
The boldest decisions In retrospect, many of the case studies have a striking common attribute: the boldest design decisions, whoever made them, have accounted for a high fraction of the goodness of the outcome. These bold decisions were made due sometimes to vision, sometimes to desperation. They were always gambles, requiring extra investment in hopes of getting a much better result. Frederick P. Brooks, Jr., The Design of Design Design with courage design