How does Spring resolve bean creation order and dependency graph internally?

Spring builds a dependency graph and initializes beans in topological order based on dependencies.

Spring uses BeanDefinition parsing to build a dependency graph. It then performs a form of topological sorting to determine safe initialization order. Circular dependencies are partially resolved using early bean references for singleton beans, but constructor cycles fail because objects cannot be instantiated partially. The BeanFactory manages this lifecycle and ensures dependencies are satisfied before initialization callbacks.