Ask HN: What mental models you found useful in delivering impact as an engineer?

I hear people talking that it takes more than great programming skills for an engineer to be successful (particularly at fast moving tech companies). As an engineer, I have learned certain mindsets that have helped me do better in my work. For example: 1) an average to a problem well understood can potentially deliver bigger impact than a great solution to a problem poorly understood, 2) not all problems are worth solving and ability to prioritize them in terms of impact is a core skill, etc.

What mental models have you found useful in your career as an engineer? Or if you're not an engineer, what mental models you think engineers need to have to deliver bigger impact?