Static typing
A language feature where code declares what kind of data it handles, so tooling catches mistakes before the program runs.
What it tells you about a developer
Choosing typed languages in personal projects, where nobody required it, shows a habit of building for correctness and for other readers. That habit correlates with professional team experience.
TypeScript, Go, Java, Rust, and C# are statically typed. Large teams prefer static typing, because the checker catches a whole class of bugs automatically and makes code readable to new team members. Python and JavaScript check types while running, and both have added optional type layers.