DMAIC is not a good fit for every situation. First, you need to recognize if the problem can be solved with the DMAIC.
The SPACE of developer Productivity framework for capture different dimensions of productivity to measure productivity in a better way.
Seven Principles for Software Development
7 SW Development Principles: The Reason It All Exists, KISS, Maintain the Vision, You Produce - Others Consume, Future, Plan re-use, Think.
Keep It Simple Stupid (KISS)
KISS - Keep it simple stupid. Most systems work best if they are simple. A simple design should be the key goal.
DRY - Don't Repeat Yourself
Don't Repeat Yourself is principle helping to avoid repetition of the same information (same code produced multiple times).
Balance the Test Pyramid poster. Test Pyramid provides a simple overview of how to balance the testing.
Create a SOLID app poster. SOLID is the collection of 5 principles that should be used as a good practice in programming.