Interfaces

2 articles

Software Engineering 05 Sep 2026 9 min read

Designing Interfaces Around Client Needs

A shared component often starts with a small interface. As more callers arrive, new methods are added until every caller sees operations it never uses. The interface still works, but it now connects unrelated needs through one contract. That matters because an interface is a dependency. When a client depends on a broad contract, changes to unrelated parts of that contract can affect its compilation, tests, mocks, generated code, or understanding of the component even when the client needs only one capability.

Software Engineering Software Design

Go 03 Sep 2026 12 min read

Understand Nil Interface Values in Go

A Go program can print an error that looks empty, enter an if err != nil branch, and still be holding a nil pointer underneath. This behavior surprises developers because it seems to violate the simple rule that “nil means no value.” The rule is still consistent. The missing piece is that an interface value has two parts: a dynamic type and a dynamic value. An interface is nil only when neither part is set.

Golang Language Features