Engineering is a world where something is always broken somewhere and there are plenty of things to complain about. It can get pretty tiring and dispiriting when all you hear is complaints about what you work on.
When you’re working with someone that impresses you, on your team or elsewhere, send an email to their boss and tell them about it. You need to keep good engineers and a constant stream of negativity is not a great recipe for preventing burnout. So, a couple times a year at least, try to send an email like this. Short and sweet is fine:
I’ve been working with so and so on project X and I just wanted to say that s/he was a pleasure to work with. S/he came up with some great ideas and was great at creating a solid architecture.
This can benefit everyone. The boss benefits by knowing the strengths of a member of his team. The engineer benefits by getting his status elevated by your comments. You benefit by having a positive attitude and by forging a potential relationship with a boss that may not previously have known you.