What is a software blueprint?

A software blueprint is a high-level plan or outline used in the development of software.

When the term blueprint is used in programming, it usually refers to one of two related, yet slightly different concepts:

• a high-level, graphical or written piece of documentation of software architecture ("blueprint for humans")

• a piece of code serving as a template for code-generating tools that build or configure applications ("blueprint for machines")

Overall, software blueprints are a powerful tool for planning, building and maintaining software projects.

And first, let's take a look into how software blueprints are used as documentation.

Blueprints as software design documentation

Blueprints may be used to design and document the architecture of applications. It serves as a high-level representation of software design that supports the development process in several ways:

As part of the planning process of upcoming feature work, a blueprint communicates implementation requirements across an engineering team more efficiently; a software architect may design a new feature and they can then use a blueprint to provide the feature requirements to the software engineers who will implement it later on.

In a similar manner, blueprints help teams consisting of both engineering and non-engineering professionals to collaborate on the development of business applications; blueprints empower stakeholders of either department to define requirements using common terminology that doesn't require in-depth, technical knowledge. This way, a software blueprinting process reduces the number of cycles needed for planning, implementing and iterating on features by getting application requirements defined well from the beginning. This in turn helps to reduce the overall development time of applications significantly.

Through this process, blueprints become an effective strategy for maintaining documentation of software architecture. As a business goes through the iterative process of blueprinting feature work upfront and implementing features according to the design, a growing documentation for the business's software architecture is created automatically.

Using Unified Modeling Language (UML) software architects oftentimes visualize the design of the systems they and their team are implementing. Many products and open-source tools support software design with UML, such as Papyrus, Visual Studio or Lucidchart.

For more insight into the rationale behind blueprints as documentation and UML specifically, you may want to continue reading "UmlAsBlueprint" by Martin Fowler.

But the term blueprint isn't only used to describe software design plans that help people to implement said software. "Blueprint" also refers to those design plans that help computers to implement software automatically.

Blueprints as automatic programming templates

In automatic programming a computer program, when run, generates code automatically based on a specific configuration. The configuration for these code generators can come from direct user input (e.g. parameters provided to a shell command) and - from blueprints.

As part of the code generation process, the blueprint outlines the layout and configuration of the resulting program. This makes the blueprint useful in scaffolding and extending applications; a software engineer who uses blueprints in their development process can focus on the implementation of the business logic itself and worry less about how their implementation fits into the code base.

Therefore when used as code generator templates, blueprints improve the immediate developer experience significantly and can reduce overall development time. Lastly, they facilitate scaling and maintaining large applications by making extending applications easier.

Many different tools and frameworks already support blueprints and code generators for developers. This includes, for example and among many others, the Python web framework Flask, the Blueprint visual scripting system of Unreal Engine, and the JavaScript framework EmberJS.

Blueprints as documentation and automatic programming tool

Blueprints are a powerful tool in planning, documenting and implementing software applications.

Blueprints - when used as documentation for software architecture - are critical for successfully planning and executing development cycles, whereas blueprints - when used as a template for code generators - are an integral part of maintaining and scaling code bases gracefully.

Have you created or used software blueprints before? Let me know in the comments below!