Design Patterns in .NET for End User — Lesson 4: Legacy Design Refactoring and Architecture Decision Challenge

Topics Covered

• Identify pattern misuse, code smells, over-engineering, and hidden maintenance costs
• Refactor an existing .NET design while preserving behavior with tests
• Document architectural decisions and validate the improved design against quality goals
• End-to-end scenario integration, decision trade-offs, and stakeholder impact
• Validation checklist, measurable acceptance criteria, and evidence capture
• Prioritized improvement roadmap, ownership, and next learning steps

Guided Practice Steps

1. Translate the lesson requirement into a clear Design Patterns in .NET for End User implementation or analysis objective.
2. Document assumptions, selected tools or features, dependencies, risks, and expected results.
3. Perform the guided task, capture evidence, and compare the result with the acceptance criteria.
4. Record issues, corrective actions, and a reusable operational or development note.

Practical Activity

Refactor a legacy design and produce an architecture decision record with validation evidence.

• Define the scenario, inputs, constraints, and expected outcome.
• Complete the activity and preserve screenshots, outputs, logs, code, or decision evidence.
• Review the result, identify gaps, and document corrective or improvement actions.

Validation Checklist

• The stated requirement and expected outcome are clear.
• Configuration, code, data, or design decisions are documented.
• Normal, boundary, failure, security, and operational considerations are reviewed.
• Evidence supports the conclusion and the next action is prioritized.

Lesson Outcome

Learners can explain and apply Legacy Design Refactoring and Architecture Decision Challenge within a realistic Design Patterns in .NET for End User scenario and support the result with validation evidence.