Practical DDD for Product Teams: Ubiquitous Language on a Deadline

Domain‑Driven Design (DDD) becomes counterproductive when treated as a months‑long analysis phase. We compress it into iterative, code‑proximate activities that keep shipping cadence high.

Start With High-Change Domains

Prioritize modeling where volatility lives: pricing rules, entitlement logic, workflow transitions—not CRUD admin zones.

Lightweight Event Storming (90 Minutes)

1. List pivotal user intents (commands).
2. Capture resulting state transitions (events).
3. Group into tentative domains based on event cohesion.
4. Extract ubiquitous terms (glossary).

Coding The Language

// Value Object Example
export class Money {
	private constructor(readonly cents: number, readonly currency: string) {}
	static from(amount: number, currency = 'USD') {
		return new Money(Math.round(amount * 100), currency);
	}
	add(other: Money) {
		if (other.currency !== this.currency) throw new Error('Currency mismatch');
		return new Money(this.cents + other.cents, this.currency);
	}
}

Test as Living Specification

We codify invariants in unit + contract tests. Glossary terms appear in test names to reinforce shared language.

Refinement Loop

• Weekly 15‑minute domain sync: new terms? ambiguous language?
• Refactor naming + boundaries opportunistically.
• Promote stable concepts to shared kernel; keep experimental ones local.

Outcome

Just enough modeling to reduce miscommunication and rework while sustaining delivery momentum.