I have seen multi million dollar projects hit the same snags, horribly under scoped all because Mr Easy didn't think about asking all of was needed. They saw the tree and missed the forest
What's the expression? "Plan your system for 100x growth, but build your system for 10x growth". Something like that except for functionality rather than scalability.
That and supporting the system. Junior engineers tend to think about building the tech, which is honestly the easy part. Keeping it working until the last of your customers are finally ready to upgrade 10 years later is harder than junior engineers tend to think.
I know it's not always easy to do this, but that really is part of the challenge. There's still too many deathmarch projects lead by people trying to do things 'the right way'. If you're working on a new project for the love of science, please make sure you're releasing something valuable every single week if not every one or two days!
I expected him to go off and actually attempt building it, that way he would get some more experience.
And he did! He went off that weekend and wrote a proof of concept route planner, it was great to see him learn something new and complex