Architecturally Significant Decisions

Part 1 of the Agile Architecture Series

Engaging in architecture within a start-up or scale-up organisation offers a unique and exciting set of opportunities that distinguish it from traditional corporate environments.

It’s an environment where architects often find themselves navigating a dynamic landscape that demands adaptability and creativity.

Photo by Martin on Unsplash

Scope and Diversity: Crucially, the scope and diversity of architectural challenges encountered across different domains can present architects with a uniquely rewarding yet equally demanding experience.

This diversity not only allows architects to explore a wide spectrum of problems but also challenges them to adapt and find innovative solutions, making their roles both intellectually stimulating and professionally enriching.

Agility and Focus: Juggling Agility and Focus in such a vast scope can be tricky. But how do we decide what’s crucial?

Well, that’s where One-Way and Two-Way decisions come into play.

One-Way and Two-Way Decisions

As a kid, one of the classic hobbies I embraced was playing with model trains, and it was an endless source of fun and imagination.

One of the earliest and most significant “one-way” decisions I had to make was selecting the gauge of the model trains. It might seem like a small choice, but in the world of model trains, it’s the decision that sets the stage for everything else. The gauge determines the size and scale of the trains and tracks, dictating which models, accessories, and scenery would be compatible. It’s akin to choosing the foundation for your miniature railway universe.

This seemingly simple choice had a profound impact on the entire journey, as it guided subsequent decisions about track layouts, locomotives, carriages, and even the landscapes I would create. It’s amazing how a single decision in a childhood hobby can teach the importance of architecturally significant choices in the broader context of life and decision-making.

Wikimedia Commons

I’m going to paraphrase a great visualisation from the The Open Group

Think about decisions as one-way or two-way doors [Think Like Amazon: Rossman 2019].

When you walk through a one- way door, if you do not like what you see on the other side, you cannot get back to the initial state. This type of decision, is difficult to reverse.

When you walk through a two-way door, if you do not like what you see on the other side, you can walk right back through the door and return to the previous state. This type of decision, is easy to reverse.

One-Way Decisions

One-way decisions are choices that significantly impact a project, system, or organisation and are challenging to reverse or modify once implemented. These decisions typically include large programs of work that have a profound and enduring impact on an organisation.

Examples of One-Way Decisions can include -

• Re-platforming your core system. This can be akin to modernising the heart of your organisation. This typically involves migrating from an existing infrastructure or architecture to a new one, often driven by the need for improved functionality, scalability, security, or compliance.
• Changing your Technology Stack (or Parts of). Another example of a one-way decision with significant implications. This decision involves migrating from one set of programming languages, frameworks, or tools to another, often with the aim of improving efficiency, reducing costs, or addressing emerging market trends.

So when it comes to Focus, it becomes critical to identify your one-way decisions, spend more time evaluating them, testing them and architecting them.

When you figure out the big, game-changing “One-Way” decisions, the other choices (should just) fall into place. Those Two-Way decisions should go hand-in-hand with and match up to the main direction that has been set.

Two-Way Decisions

Two-way decisions, on the other hand, are choices that offer flexibility and the possibility of revisiting the decision later in the project.

Key characteristics of two-way decisions include:

1. Flexibility: Two-way decisions allow the team to experiment and adjust based on evolving requirements or new information.
2. Lower Impact: These decisions have a lower immediate impact on the overall architecture and can be revisited if necessary.
3. Examples: Include adopting a specific library or building a feature for a mobile app. Also, many Two-Way decisions are usually made within the team or pod and don’t have a complex integration requirement.

Actually, the Two-Way Decisions don’t always just fall into place. There can be a lot of wastage around doing things the wrong way, then needing to fix them up and trying again (More on how to avoid this problem in Part 2 of this series).

Conclusion

• Architecturally Significant Decisions hold the power to shape a project, system, or organisation. Recognising these decisions is crucial to channel time and resources effectively. Equally vital is avoiding unnecessary “governance” on less important decisions that can be easily undone.
• One-way decisions should have focus and oversight. These are the architecture decisions that are important to the organisation and set the stage for future work.
• Two-way decisions benefit from a lighter touch when it comes to governance and oversight. These choices empower teams to innovate and deliver swiftly, enabling flexibility and agility in response to evolving needs and opportunities.