Suggest an editImprove this articleRefine the answer for “What are Mediator's downsides?”. Your changes go to moderation before they’re published.Approval requiredContentWhat you’re changing🇺🇸EN🇺🇦UAPreviewTitle (EN)Short answer (EN)The **Mediator** pattern solves the problem of excessive links between objects, but it can itself create **new complications** when overused. **Key point:** when misapplied, Mediator creates a new point of fragility, an overloaded coordinator that concentrates too much logic and too many dependencies.Shown above the full answer for quick recall.Answer (EN)ImageThe **Mediator** pattern solves the problem of excessive links between objects, but it can itself create **new complications** when overused. --- ### 1. **The Mediator Can Become a "God Object"** The main risk is the gradual **growth of the mediator**. When all interaction is concentrated in one class, it starts managing too many processes, from UI logic to business rules. > Eventually Mediator turns into a "monolithic controller" > where changes in one part affect everything else. --- ### 2. **Difficulty Understanding and Maintaining the Logic** The system's behavior becomes **less transparent**, components no longer interact directly, and understanding *who calls what* requires studying the mediator's code. > This reduces readability, especially with many events and states. --- ### 3. **Scalability Problems** As the number of participants grows, the Mediator has to account for more combinations of interactions. This complicates the structure, and any new logic requires changing the mediator, which partially violates the *open/closed* principle (OCP). --- ### 4. **Risk of Excessive Centralization** Instead of many dependencies between objects, you get **one giant dependency on the mediator**. All components become **loosely coupled to each other**, but **tightly coupled to the Mediator**. --- ### 5. **Reduced Performance (in Some Scenarios)** If the mediator handles a large number of events or notifications, an **extra layer of calls** and temporary overhead can appear. --- ### **Conclusion** | Disadvantage | Essence | |---|---| | "God object" | The mediator becomes overloaded with logic | | Loss of transparency | Hard to understand who calls whom | | Violation of OCP | Any new interaction requires changing Mediator | | Excessive centralization | Everyone depends on a single mediator | | Possible overhead | Extra steps when passing messages | --- **Summary:** The **Mediator** pattern reduces coupling, but when misapplied it creates a **new point of fragility**, an overloaded coordinator that concentrates too much logic and too many dependencies.For the reviewerNote to the moderator (optional)Visible only to the moderator. Helps review go faster.