Design Patterns
Design Patterns are proven solutions to common problems in software development.
Classification
- ComplexityMedium
- Impact areaTechnical
- Decision typeDesign
- Organizational maturityAdvanced
Technical context
Principles & goals
Use cases & scenarios
Compromises
- Misunderstandings about the application of patterns can lead to errors.
- Excessive reliance on patterns can stifle creativity.
- Incorrect implementation can lead to performance issues.
- Offer regular training on design patterns.
- Document and share design patterns within the team.
- Gather feedback on design decisions.
I/O & resources
- Software Requirements
- Existing Design Patterns
- Team Members with Experience in Design Patterns
- Reusable Components
- Documentation of Design Decisions
- Improved Software Architecture
Description
Design Patterns provide reusable solutions to common challenges in software architecture and development. They help developers apply best practices and improve communication within teams.
✔Benefits
- Increased efficiency in development.
- Improved maintainability of the code.
- Better team communication and collaboration.
✖Limitations
- Can lead to over-engineering if not applied appropriately.
- Requires a certain level of experience to be used effectively.
- Not all patterns are suitable for every situation.
Trade-offs
Metrics
- Code Reusability
Measurement of code reusability through design patterns.
- Error Rate
Proportion of errors arising from the application of design patterns.
- Development Time
Time required to develop a feature using design patterns.
Examples & implementations
Singleton Pattern in a Database Connection
The Singleton pattern is used to ensure that only one instance of the database connection exists.
Observer Pattern in a Notification System
The Observer pattern allows multiple objects to respond to changes in a specific object.
Factory Pattern for Object Creation
The Factory pattern is used to create objects without specifying the exact class.
Implementation steps
Identifying relevant design patterns for the project.
Training the team in the selected design patterns.
Implementing the design patterns in the software.
⚠️ Technical debt & bottlenecks
Technical debt
- Outdated implementations of design patterns.
- Lack of documentation for used patterns.
- Insufficient training of the team on design patterns.
Known bottlenecks
Misuse examples
- Using the Singleton pattern in a non-thread-safe environment.
- Applying the Observer pattern without proper management of subscriptions.
- Incorrect implementation of the Factory pattern leading to unexpected objects.
Typical traps
- Assuming that a pattern is always the best solution.
- Overlooking the specific requirements of the project.
- Ignoring team dynamics and skills.
Required skills
Architectural drivers
Constraints
- • Technological constraints of the platform used.
- • Organizational policies and standards.
- • Time constraints for implementation.