TypeScript 5.x Features Senior Teams Actually Use

TypeScript's velocity slowed on purpose: correctness over novelty.

High-impact additions

• satisfies for config objects without widening literals
• Improved control flow on discriminated unions in switch statements
• Faster builds via project references and incremental caches

Team policy example

const routes = {
  home: "/",
  blog: "/blog",
} as const satisfies Record<string, `/${string}`>;

What we skipped

Exotic conditional types in application code—reserve them for library authors.

Hiring signal

Candidates who explain when not to use generics outperform template magicians every time.