In 2025, too many Go projects still misuse interfaces — leading to nil surprises, unsafe type switches, and brittle abstractions.

⚡ Key points every Go dev should master:

• Interfaces store type + data, so a nil pointer ≠ nil interface.
• Empty interface {} is a last resort, not a default.
• Keep interfaces small and local — easier to mock, easier to swap.
• Type switches unlock real power (when used with care).
• Polymorphism? Yes. Overengineering? No.

💡 Learn where to declare them, when to assert, and how Go’s dynamic dispatch actually works behind the scenes (no "Dog/Cat" clichés).

https://levelup.gitconnected.com/go-interfaces-made-practical-in-2025-from-basics-to-real-world-use-04307f0fe02a