In general the talk was good, I could give you a feedback for a few aspects.
When I'm in a talk I always look for a few things, like:
- The mind blow factor: some real new thing that I/spectators never thought about!
- The funny factor: some cool stories which came with your experience would complement nicely the part about the why people leave companies and the joke about the developer which stay in the company but is not learning!
For me those things really makes the talk more enjoyable during time!
You can also have a slight improvement on the slides, the focus was almost completely on what you were saying, maybe more pictures could help!
The content of the talk was good and had plenty of tips for new developers.
However, the talk didn't quite match my expectations after reading the title and abstract. It felt more like a "level up yourself" instead of your team.
My suggestion would be to shift focus more towards the non-programming aspect of working in a team, perhaps offer more solutions on how to improve a team instead of one developer in the team and think of activities inside the team that can contribute to that. Not to say you don't touch on that subject already, but perhaps more focus on that would fit the title better.