What is Spring Boot auto-wired ambiguity resolution strategy?

Spring resolves multiple bean candidates using @Primary, @Qualifier, and bean name matching.

When multiple beans of the same type exist, Spring first checks for a @Primary bean, then looks for @Qualifier annotations, and finally falls back to matching bean names. If ambiguity remains unresolved, Spring throws NoUniqueBeanDefinitionException. This mechanism ensures deterministic dependency resolution in complex applications.