This is exactly what I've been doing for a while. I check whether my ideas are SOLID and this have been enough so far. When I change something it only affects i

This is exactly what I've been doing for a while. I check whether my ideas are SOLID and this have been enough so far. When I change something it only affects its immediate surroundings so things are easy to fix. If something breaks it doesn't cascade throughout the system. I also like to have interfaces for all non-trivial things so I can stub them when I test and provide multiple implementations for different use cases (strategy). With this I feel that I'm insanely productive.