Technique · Static analysis

Type checking

Proves call sites and data shapes agree across modules: wrong types, unhandled null or None, signatures broken by a change.

Sub-techniques

Gradual typing V1006.001

Type-check annotated code first and tighten strictness per module.
Strict mode V1006.002

Disallow implicit any, untyped definitions and unchecked optional access.
Compiler as checker V1006.003

In compiled languages the build is the type check; a failing build is this check failing.