Introduce a design pattern

The following code has this structural problem: [Describe the problem, e.g. tight coupling, repeated conditionals, hard-to-test dependencies]: [Paste code]. Identify the most appropriate design pattern from the GoF catalogue or architectural patterns such as Strategy, Observer, Factory, Repository, or Decorator. Show a before-and-after refactor that applies the pattern and explain why this pattern is the right fit for this specific problem.