Five things every developer should know about software architecture by Simon Brown

Summary

This talk emphasizes that software architecture is not about big design upfront but about setting a starting point and direction. It highlights the importance of technical leadership, coding, and collaboration in architecture roles, and introduces the C4 model for visualizing software architecture. The speaker also discusses the misconception that agility and architecture are competing forces, asserting that a good architecture enables agility.

Takeaways

• 🤔 Software architecture is not about big design upfront; it's about making informed, iterative decisions that reflect what will be built and have a chance of working.
• 🛠️ The Agile Manifesto promotes responding to change over following a plan, but this has sometimes been misunderstood to mean skipping design altogether, which can lead to technical debt.
• 🔍 The right amount of upfront design depends on the context, such as whether you're working on a system replacement project with well-known requirements or a startup looking for feedback and the potential to pivot.
• 🎯 Good architecture involves making significant decisions with high costs of change, such as the choice of language, frameworks, and data models, which should be considered carefully before being embedded into the codebase.
• 👷‍♂️ Technical leadership is essential on every team, providing guidance on architectural decisions, managing risks, and ensuring code quality without being overly prescriptive.
• 👥 The software architecture role involves coding, coaching, and collaboration, emphasizing the importance of architects being involved in the actual building process to maintain a practical perspective.
• 🧠 The importance of soft skills in technical leadership, including communication, motivation, and influence, which are crucial for aligning team efforts and facilitating discussions.
• 🛑 The C4 model for visualizing software architecture offers a hierarchical set of diagrams that help in creating a clear, structured representation of the system at different levels of abstraction.
• 🔧 A good software architecture enables agility by providing a well-structured foundation that allows for continuous improvement and adaptation to change without causing a ripple effect across the system.
• 🚫 UML is not necessary for effective software architecture communication; a common language and clear, simple diagrams can be more effective in conveying design intent and understanding.
• 🔄 The key to a successful architecture is not following trends or hype but applying thoughtful, justified design decisions that stand the test of time and the needs of the project.

Q & A

What are the two key questions a software developer should ask while doing architecture design?

The two key questions are: 'Do these pictures reflect what we think we're actually going to build?' and 'Does this design have a chance of working for me when I'm doing upfront design?'

Why is 'Big Design Up Front' considered a myth in software architecture?

It's a myth because historically there was a tendency towards Big Upfront Design, but it often leads to long feedback loops and by the time something is delivered, people's requirements have changed. Agile development approaches advocate for iterative and incremental design instead.

What does the Agile Manifesto value more: responding to change or following a plan?

The Agile Manifesto values 'responding to change over following a plan', emphasizing adaptability and flexibility in software development.

What is the main issue with teams that jump from Big Design Up Front to no design at all?

The main issue is that they can accumulate technical debt very quickly and end up with chaotic code bases and inconsistent approaches to solving problems.

What is the recommended approach to determine how much upfront design should be done?

The recommended approach is to do 'just enough upfront design' depending on the context of the project, which could vary from a well-known system replacement project to a startup with uncertain requirements.

What is the significance of architecture according to Grady Booch's quote?

According to Grady Booch, architecture represents the significant decisions where significance is measured by the cost of change, focusing on the hard-to-change aspects of a system.

Why is it important for architects to write code or be involved in the building process?

It is important for architects to write code or be involved in the building process to maintain a connection with the code, keep their skills up to date, and to learn from their own mistakes, ensuring grounded and practical design decisions.

What is the C4 model for visualizing software architecture?

The C4 model is a set of hierarchical abstractions that allows for creating a set of hierarchical diagrams at four levels: context, containers, components, and code, aiming to improve the clarity and effectiveness of architectural diagrams.

How does a good software architecture enable agility?

A good software architecture enables agility by providing a well-structured and modular codebase that allows for easy changes and adaptations, reducing the ripple effect of modifications and supporting continuous improvement.

Why is it recommended for software architects to avoid extremes like a monolithic approach or a microservices approach without proper consideration?

It is recommended to avoid extremes because each approach has its own set of challenges and benefits. A well-structured monolith can be more maintainable and performant for certain types of applications, while microservices offer benefits in terms of scalability and team autonomy but can introduce complexity and latency.

What is the role of technical leadership in software architecture?

Technical leadership in software architecture is about injecting technical guidance into development teams, managing architectural drivers, designing the software, overseeing technical risks, and ensuring quality and consistency in the codebase.