@Eager annotation for eager initialization of @ApplicationScoped beans — the CDI equivalent of EJB’s @Startup

@AutoClose annotation — beans implementing AutoCloseable are now automatically closed during destruction without the need for explicit @PreDestroy or @Disposes methods

Asynchronous method invokers via the new AsyncHandler API

Programmatic registration of BuildCompatibleExtension in CDI SE

SyntheticInjections for injection points in synthetic beans

Global scopes — application scope is now global

Support for parameterized types in @Registration

Removal of deprecated EL-related BeanManager methods (moved to ELAwareBeanManager in CDI 4.1)

Removal of SecurityManager references

Trimming a non-explicit bean archive is now correctly treated as a deployment problem (WELD-2832)

Optimized how Weld keeps references to dependent instances within CreationalContext (WELD-2834)

Fixed ClassCastException when unwrapping proxied EntityManager (WELD-2245)

Fixed reflection discovery strategy incorrectly discovering beans with just inherited BDA in SE (WELD-2826)

Startup event is now fired in a synchronized block (WELD-2827)

Ensured proxy target JPMS modules can read Weld JPMS modules (WELD-2828)

ProcessSyntheticAnnotatedType now correctly fired for types added via configurators (WELD-2831)

Weld#addExtensions no longer swallows exceptions (WELD-2833)