How can you maintain flexibility in your architecture?

1. Modularity and Decoupling: Modularity: Designing independent modules for flexible development. Techniques: encapsulation, API design, dependency injection. Decoupling: Minimizing module dependencies for agility. Techniques: message queues, event-driven architecture, dependency inversion. 2. Iterative Development: Definition: Incremental software development for continuous feedback. Implementation: Use Scrum, Kanban, and user stories. 3. Adaptive Planning: Definition: Continuously adjust plans for responsiveness. Implementation: Regular backlog grooming, sprint planning, retrospectives for Agile adaptability.

Architecture Tiering, not in terms of technology, but considering business use cases as a critical input for modularising our components will be extremely helpful in creating a flexible architecture. Where business needs utmost flexibility, we need to make as decoupled and as configurable as possible. Aspects that are less frequent to change can be a bit more tightly coupled. The same principles need to be applied while defining data contracts between systems. Smart placeholders can be leveraged to maintain some flexibility.

Apply SOLID principles: - S: Single responsibility => One class one responsibility - O: Open Close => open for extension but closed for (interface) modifications. - L: Liskov Substitution => program with interface, should be able to pass a Derived Class object, where a Base Class object is expected. -I: Interface Segregation => program with interface. -D: Dependency Inversion => depend on interfaces and abstractions and not on concrete implementations.

El principio de apertura-cierre en el desarrollo de software propone que las entidades deben permitir la extensión pero resistir la modificación. Dise?ar componentes con abstracción, herencia, polimorfismo y dependencias inyectadas facilita la adición de funciones sin alterar el código existente. Esto potencia la reutilización, el mantenimiento y la prueba del código al reducir el riesgo de errores. Al seguir este principio, se fomenta un desarrollo más eficiente, flexible y resistente a cambios, mejorando la calidad y sostenibilidad del software.

The Open/Closed Principle (OCP) suggests that you add new features without changing the existing code. For example, let's say you have a basic `HTTPClient` that makes requests. According to OCP, you can add new capabilities, like handling authorization, without changing the original `HTTPClient` code. Instead, you create a separate component called `AuthorizationHTTPClientDecorator` that adds the authorization functionality. This way, you're extending the capabilities (open for extension) without modifying the core `HTTPClient` (closed for modification). So, the Open/Closed Principle encourages designing software in a way that allows for easy extension without messing with existing, working code.

Well, that in principle applicable to all the architectures…building atomic functions combining together, delivering the desired end functionality This allows functions to be common, reusable and the most important easy to decouple when required The only trade off is to keep a balance between integration overheads if the functions are delivered through different systems

Before opting to use a microservices architecture, thoroughly assess the components you're working on. Ensure that the services are truly autonomous and aren't interdependent. Attempting to create dependencies within a microservices setup can lead to bottlenecks and heightened latency.

Keep in mind that the "fail fast" approach doesn't excuse delivering subpar work. When dealing with a production system, failing fast is all about being able to make swift changes whilst consistently gathering feedback. To execute this successfully, it's crucial to maintain proper testing, automated quality gates, and a robust continuous integration and deployment pipeline. These elements provide the assurance to 'fail fast' while maintaining confidence, security and stability.

Fail fast should be the approach in this fast paced environment. No longer we have leisure of time to work on something for months only to realize there is no market-fit later. Embrace feedback, experiment, validate assumptions, test hypotheses, and learn from failures.

While flexibility is essential, it doesn't imply an open door for anything and everything. Feedback may not always conform to the rules of sanity and scope. Conflicts often emerge when Architects aren't actively engaged in defining the vision from the outset, appearing as guests later on. To mitigate this, it's crucial for Architects to share the product vision and articulate it as effectively as the product team. This ensures a unified understanding and proactive participation in shaping the product's trajectory.

It's important to write your tests in a way that they are not tightly coupled to your implementation. Ensure that you test your unit or module from the entry point rather than at a per class level. This will make it easier to refactor when there is a need to change your internal architecture.

A periodic evaluation of the technology stack in use (Continuous Technology Evaluation) is also a good practice in this context. The outcome should be an updated tech roadmap which can be used as valuable input when planning for refactoring & evolution as well as potential deprecation or even replacement. All of this is of course easier said than done, so it is important to keep in mind what might be key enablers such as: Infrastructure as Code, CI / CD, automated testing, proactive monitoring, etc. An option which is not for every case but can be quite powerful if applicable is an open-sourcing strategy, where refactoring and evolution is driven not only by the maintainers of the software but also by developer communities.

Break down your system into smaller, independent units with clear boundaries and responsibilities. This enables independent scaling, development, and deployment, making the system more adaptable to evolving needs. Leverage automation tools to automate repetitive tasks and build pipelines for continuous integration and delivery. This streamlines the development process and reduces the cost of adapting to change. Integrate monitoring and logging tools to gain insights into system performance and identify potential issues early on. This allows you to react quickly to changes and proactively address challenges.

Write tests. While the points articulated in this article are valid, consider that your application is in a constant state of evolution and it's never finished. Without a robust test suite, in a real word scenario, you lack the assurance needed to modify your application confidently. This, in turn, limits its flexibility, regardless of how modular it is. Tests also can act as documentation. enabling other developers to understand your code better and make changes with confidence.