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
Technical debt as a lack of understanding An Article by Dave Rupert daverupert.com "If you develop a program for a long period of time by only adding features but never reorganizing it to reflect your understanding of those features, then eventually that program simply does not contain any understanding and all efforts to work on it take longer and longer.” — Ward Cunningham softwareprocesscode