Sure, three things stand out:

1. Stricter inference. Generic narrowing now propagates through conditional types more aggressively, so a lot of as casts can come out.

2. Faster project references. Incremental builds no longer re-walk unchanged graphs, so large monorepos see 30 to 50% wins out of the box.

3. Native decorators. The TC39 stage-3 decorator shape is now the default, and the legacy flag is deprecated.