One of the goals of an engineering leader is to level up their engineers. Personally, I find that there is nothing more rewarding. Helping a junior become a well-respected senior is one of the best feelings. You can help them to level up by making sure they get a challenging project. But how do you know what projects are a good fit? The Goldilocks rule is here to help you figure that out!
Human psychology states that people need to be challenged. There are some requirements for the challenge. Too little challenge and a person gets bored. Too much of a challenge and you can overwhelm them. The challenge needs to be just right. But what is just right?
The Goldilocks Rule states that humans experience peak motivation when working on tasks that are right on the edge of their current abilities. Not too hard. Not too easy. Just right.
I like to compare finding a challenge for an engineer with running. I like running, but I cannot run a marathon. With extensive training I might, but not right now. For instance, a good challenge ratio for me would be to focus on moving from 5k's to 10k's. If I get there, train for a half marathon before going for the full 42 kilometers.
You may not give a junior the full responsibility of a project that can make or break your company. But a smaller scoped project might fit. The goal is to pick something that is just bigger than what they have done to that point.
I'm a big fan of giving people chances. The next time there is a project take a look at your leaders. Do the same engineers always lead all the projects? This might be your perfect opportunity to give someone a chance to lead a project that is just on the edge of their current abilities.