An engineer that builds software to a known quality and time will generally use a V-model (all requirements are defined, then validated) and won't spend most mornings standing around talking about new ideas their breakfast acid gave them to try out in the next 24 hours. The engineer will also generally not commence "construction" until "design" is near or substantially complete, or else budget/schedule/quality are unable to be predicted, even by god.
It all leads back to the eternal question in software, "how will I know when I am finished?" (the software). "When you have done what you said you will you do". At which point it often breaks down because "make something cool" isn't usually a measurable objective that satisfies a requirement, unless you work for Hasbro, maybe.
Engineered software is built and tested to satisfy specific requirements that solve a problem (to meet a need). It is often perceived as expensive and slow, but is the process to follow for a chance of known and measureable results.
That is engineering - designing, then building, then testing and validating that the requirements are being met, satisfying a need.
TDD starts to get you near there, if all the tests are written first, or at least to some sort of hierarchy of detail concurrently.
Starting something you don't know how it's going to end is speculative exploration, and there is nothing wrong with that, but it is not engineering and in engineering projects is usually limited to very small "proof of concept" phase up front before most aspects of design are fixed and detailed engineering commences.
Quality in software is not as nearly gray as many like to think, it is just the cost to not operate in a way where 90% of the outcomes fall in the gray area is perceived as too expensive/slow.
And also because if you are not engineering a bridge and you can make "pivots" 17/18ths of the way through, but just at way greater risk/desperation than any sane engineer would do unless at war or halfway back from the moon and out of oxygen.
Finally, the engineer will follow practices and procedures that they are able to, and prepared to, defend in court if someone dies as an associated result and the grieving widow wants revenge.
