I think as a manager it’s often the small things that can have the biggest impact. At my current company I helped revive a meeting we have called Code Read. It’s basically a meeting where the engineers sit down and go over the commits from the last couple of days focusing on ones that implement something novel or are a good learning opportunity for other devs. Sometimes it’s as simple as “what’s DRY” or “what’s a decorator” and other times it’s a deeper discussion like the performance impact of switching to immutable data structures.
It’s been especially impactful because I also pushed for us to hire some junior engineers and it’s been a wonderful way for them to get exposed to a lot of great lessons and feedback outside of the PRs they already have. Since then, those engineers have all come into their own and some of them are becoming heavy hitters.