I think the key insight is that you can spend all your time as an engineer doing softer less technical work, but if you’re doing that as a junior engineer you s

I think the key insight is that you can spend all your time as an engineer doing softer less technical work, but if you’re doing that as a junior engineer you should maybe just consider management. That type of work is not going to level up your technical abilities and make you an impactful individual contributor but it will level up your management abilities. Likewise, it's usually counter-productive to spend all your time coding if you’re a new manager. The most effective way I've seen for this to progress is for the more senior engineers to spend less time coding and more time doing project level spec and design work with the balance shifting over time. Usually a senior engineer is going to be better at the spec work because they have more context and domain knowledge. I would be critical of throwing everything in the category of "glue" though, because delegating purely non-technical work to someone non-technical is also an important skill for engineers.