Struggling with Rigid Aggregates? Shift to Decision-Driven Modeling with Disintegrate!

If traditional aggregate-centric event sourcing feels too rigid or limiting, it’s time to rethink your approach. Introducing Disintegrate, a Rust library that moves the focus away from aggregates and puts Decisions at the heart of your business logic.

Why Aggregates Alone Aren’t Enough

Aggregates have been the foundation of event sourcing for years, but they often lead to inflexible designs that are hard to evolve. Complex business rules spanning multiple aggregates become cumbersome, and evolving state models can get tangled in aggregate boundaries.

Disintegrate’s Game-Changing Concept: Focus on Decisions

Disintegrate shifts the paradigm by centering your domain logic around Decisions—business rules that consume events and produce new events—rather than solely on aggregates. This approach enables you to:

• Capture complex business invariants that span multiple aggregates or entities.
• React to and compose events more naturally and flexibly.
• Write clear, testable, and maintainable domain logic using its intuitive TestHarness.
• Model your domain as a set of event-driven decisions, not just state containers.

What This Means for Your Rust Projects

• More Expressive Models: Decisions allow you to encapsulate business logic where it belongs—at the point of making choices based on event history.
• Easier Evolution: As requirements change, you can adjust decision logic without being constrained by aggregate structure.
• Improved Testability: Disintegrate’s given-when-then testing style focuses on inputs (events) and outputs (decisions/events), making your tests more meaningful.

Quick Example: Writing a Decision Test

#[test]
fn it_processes_withdrawal_decision() {
    disintegrate::TestHarness::given([
        DomainEvent::AccountOpened { account_id: "acc123".into() },
        DomainEvent::DepositMade { account_id: "acc123".into(), amount: 100 },
    ])
    .when(WithdrawAmount::new("acc123".into(), 50))
    .then([DomainEvent::WithdrawalProcessed { account_id: "acc123".into(), amount: 50 }]);
}
        

Ready to Move Beyond Aggregates?

If you want to build event-driven systems in Rust that are flexible, testable, and aligned with evolving business needs, Disintegrate offers a fresh, powerful approach.

🔗 Discover Disintegrate on GitHub

🔗 Read the docs

#RustLang #EventSourcing #CQRS #DomainDrivenDesign #Decisions #SoftwareArchitecture #RustDevelopers #OpenSource