Senior has accumulated more technical knowledge, learning experience and soft skills so now his technical knowledge should contain:
- Knowledge of multiple 3rd party libraries
- Accumulation of solutions for various errors encountered before
- Usage of patterns / dedication to writing clear and clean code
- Ability to easily understand the connections between system components
- Solutions to common tasks are uneventful
Learning at this stage:
- Is vastly improved as previous experience is strong foundation for learning new techs
- There is less bandwagon thinking about technologies and accepting the hype
- More thought is given on how to spreading the knowledge to other colleagues
- Embracing code quality tools like auto formatters, linters
- More knowledge is gained about bigger picture, ie MVC vs CQRS approaches in structuring the app
Soft skills also get a bump up:
- The self care gets a priority to prevent burnout
- Relaxed attitude and improved approachability
- Smarter suggestions on different approaches to solving the problems
In short, senior can handle any task thrown at them, and can also help shape the implementation of the project