Merging and verifying frequently.
WHAT IT MEANS
Changes are merged into the main line frequently, and automatically verified each time.
WHAT IT REQUIRES
Version control Automated checks A system running them on every change
WHAT THE CHECKS SHOULD INCLUDE
The code builds or installs Tests pass Static analysis finds no new problems Formatting is correct No secrets are present
WHAT THAT ACHIEVES
Problems are found within minutes, by the person who caused them.
WHY THAT MATTERS
A problem found immediately is cheap.
The same problem found in production is expensive.
WHAT IT PREVENTS
The main branch being broken without anyone knowing Problems accumulating until a release Integration surprises after weeks of separate work
WHAT TO START WITH
Running your tests automatically on every change.
WHAT TO ADD NEXT
Static analysis and formatting checks.
WHAT TO ENFORCE
That checks must pass before merging.
WHAT TO KEEP
The checks fast, or people work around them.
