---
title: "Duck Typing and Inheritance in Ruby"
url: https://daily.dev/posts/duck-typing-and-inheritance-in-ruby-q0pcc61at
source_url: https://develclan.com/duck-typing-inheritance-ruby
type: article
source: "Ruby Flow"
published: 2026-05-20T11:22:08.605Z
updated: 2026-05-20T11:22:31.258Z
tags: ["ruby"]
reading_time: 15
upvotes: 0
comments: 0
language: en
---

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# Duck Typing and Inheritance in Ruby

**[Ruby Flow](https://daily.dev/sources/rubyflow)** · 15 min read · 0 upvotes · 0 comments

## Summary

A deep dive into Ruby's two main polymorphism mechanisms: duck typing and classical inheritance. Using a payment processing system as a running example, the post explains how to identify hidden duck types by spotting case-on-class antipatterns, how to build implicit interfaces enforced through RSpec shared examples, and when to prefer inheritance instead. For inheritance, it covers the promote-not-demote refactoring strategy, the Template Method pattern, and Hook Messages as a way to eliminate hidden super coupling. Concludes by connecting both techniques to the Liskov Substitution and Open/Closed principles.

## Full article

daily.dev links to this article rather than hosting it. Read it at the original source: <https://develclan.com/duck-typing-inheritance-ruby>

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Tags: [#ruby](https://daily.dev/tags/ruby)

[View this post on daily.dev](https://daily.dev/posts/duck-typing-and-inheritance-in-ruby-q0pcc61at)