In this insightful post, David Fowler shares how Aspire brings the discipline and reusability of software engineering to infrastructure, enabling scalable and composable deployment with strongly-typed resources and hosting integrations.

Aspire: Bringing Reusable, Strongly-Typed Infrastructure Modeling to Application Lifecycles

Author: David Fowler

In software engineering, building reusable systems is second nature: we define clear interfaces, encapsulate complexity, and rely on types to validate contracts during compile time. This rigor enables software to scale—allowing developers to confidently include libraries from other teams or vendors and “just expect them to work.”

However, this discipline typically dissolves as we enter deployment: CI/CD pipelines, infrastructure-as-code, shell scripts, and YAML files. Instead of a cohesive system, the process becomes a tangle of disparate tools, formats, and conventions. Best practices are inconsistently shared through wiki pages, Bash snippets, or markdown documentation.

Aspire: Introducing Systematic Reusability to Infrastructure

Aspire proposes a solution: transforming the ad-hoc world of deployment into a disciplined, model-driven system inspired by proven software engineering concepts.

The Core Concept: Resources

At Aspire’s heart is the resource: the atomic unit describing any application requirement—processes, containers, databases, queues, or external dependencies.

  • Interface Exposure: Resources have well-defined interfaces and behaviors.
  • Composability: They can be referenced and composed with each other.
  • Mode-Awareness: They support different modes—executed in development, emitted during publishing.
  • Extensibility: New resources can be defined, executed, and emitted, allowing for cross-project and cross-team reuse.

Hosting Integrations: Packaging Infrastructure Logic

If resources are atoms, hosting integrations are molecules. A hosting integration packages a resource type, its defaults, and full lifecycle, similar to a NuGet library but for application behavior:

  • Standardization and Reuse: For example, a team can encapsulate Redis usage, including configuration, environment-dependence, health checks, and connection wiring.
  • Simple, Uniform APIs: Developers just call methods like builder.AddRedis(), receiving a consistent, policy-compliant resource without learning the underlying details.
  • Encapsulation: Integrations ensure best practices and details are systematically embedded, not scattered across documentation.

Strong Typing: Safety and Composability

Aspire leverages strong typing for clarity, composability, and safety:

  • Modeled Behavior and Interfaces: Instead of bags of strings or ad-hoc scripts, Aspire resources expose real interfaces.
  • IDE and Compiler Support: Modern tools assist discovery and catch mistakes at compile time.
  • Compositional Power: Typed resources can interoperate in ways that scale and are testable.

By contrast, traditional deployment documentation (e.g., command-line flags, shell scripts shared in markdown or Slack) is helpful for people, but not inherently reusable, testable, or versioned in code.

From Documentation to Code Encapsulation

Aspire’s approach turns tribal, textual deployment knowledge into composable, reusable code units:

  • Examples:
    • NGINX configurations are encapsulated as reusable resources.
    • Dev/test/prod strategies for PostgreSQL are modeled once and reused.
    • Internal platforms with custom CLIs are integrated natively into Aspire models.
  • Once modeled as a resource, these workflow pieces are referenced, executed, and published just like application code.

An Open, Extensible Resource System

Aspire is founded on openness. The resource model is not fixed or closed:

  • Model Any Service: Resources can represent cloud services, local tools, containers, third-party platforms, etc.
  • Customizable Execution/Publishing: Developers define how resources run, connect, or deploy.
  • Reusable Hosting Integrations: Anyone can prepare hosting integrations that standardize behaviors and practices for their context.
  • Developer Platform Foundation: Flexibility allows Aspire to be adopted as the core of an internal developer platform.

Closing: Structured, Scalable DevOps for the Application Lifecycle

Aspire applies the rigor of software engineering to the messy, ad hoc world of infrastructure and deployment. By making resources first-class and promoting hosting integrations, it:

  • Brings reusability, composability, and enforceable standards to infrastructure work.
  • Enables teams to grow and collaborate without duplicating tribal deployment knowledge.
  • Lays a foundation for scaling software and platform engineering with safety, reliability, and repeatability.

Aspire’s model aims to ensure that, just as code is modular and scalable, so too are the systems around deployment and infrastructure management.

This post appeared first on “David Fowler’s Blog”. Read the entire article here