Design == Engineering
Design and Engineering are interchangeable terms.
Both are creative intentionality. This intentionality instills a direction towards a solution in otherwise unknown ways.
Both accumulate knowledge by traversing different contexts. As one experiences or articulates different contexts of both the problem and adjacent domains, knowledge accumulates to jump-start a possible new solution. For example, when faced with a structural problem, exploring biomimetics can provide a fresh platform from which to find solutions.
Both provide—often non-linear, iterative, systemic—affordances of solutioning. Whether it be the double-diamond, iterative, agile, sigma-six, co-creative, or personally defined methodology or practice, many approaches and tools exist to bootstrap design and engineering.
Both have been subject to overly reductionistic applications to short-cut their affordances. People who want to skip the creative, explorative, knowledge-building work to find an answer undervalue the affordances of both design and engineering. By appending the word 'thinking' to the respective term and hardly practicing it, they unknowingly disregard the keys to the knowledge and affordances that both provide.
Design and Engineering, Engineering and Design, are different symbols for the same discipline.
Those who believe differently:
fail to understand 1, 2
have fallen prey to 4 often shortly after an epiphanic discovery of 3