How do you resolve Circular Dependencies in DI?
Updated Apr 28, 2026
Short answer
A circular dependency happens when Service A depends on Service B, which depends on Service A.
Deep explanation
This causes an infinite loop during resolution. The best solution is architectural: refactor the code to extract the shared logic into a new Service C. If refactoring is impossible, you can use Lazy Injection (delaying resolution until use) or Property/Setter injection to break the constructor loop.
Real-world example
An OrderService needs a NotificationService to send alerts, and the NotificationService needs the OrderService to lookup order details. Refactor to extract OrderLookupService.
Common mistakes
- Ignoring the architectural flaw and using Service Locator hacks to bypass the loop.
Follow-up questions
- What happens if a DI container detects a circular dependency without Lazy evaluation?