ES2020+ syntax, async plumbing, and event-driven browser code.

Typed application code and maintainable contracts.

Progressive component authoring for rapid single-page apps.

Utility-first styling for rapidly composed interfaces.

Nesting, variables, and mixins for maintainable stylesheets.

Build tooling, services, and content pipelines.

Scripting, data wrangling, and service automation.

Native modules and performance-sensitive components.

Low-level systems work close to the runtime.