TDD Swarm Development Methodology

Traditional sequential development (one team per week) was too slow for healthcare delivery timelines. HDIM needed concurrent team execution (RED-GREEN-REFACTOR cycles) to accelerate feature delivery while maintaining quality.

Problem: Phase 5 (4 event services) would take 8 weeks sequentially—unacceptable for healthcare innovation cycles

Description: RED phase (all teams write tests in parallel) → GREEN phase (teams implement independently) → REFACTOR phase (consolidate and optimize)

Results (Phase 5):

Pros:

Cons:

Estimated Effort: 2-week per feature

Risk Level: Low (proven in Phase 5)

Description: Team 1 → Team 2 → Team 3 → Team 4 (one after another)

Results:

Pros:

Cons:

Risk Level: High (slow delivery)

We chose Option 1 (TDD Swarm) because:

All teams write failing tests defining expected behavior:

@Test
void shouldCreatePatientEvent_WithValidData() {
    // Arrange
    PatientCreatedEvent event = new PatientCreatedEvent(...);

    // Act
    eventStore.append(event);

    // Assert
    assertThat(eventStore.getEvents()).contains(event);
}

Teams implement code to pass tests:

public void append(Event event) {
    eventStore.insert(event);
}

Teams consolidate, optimize, and integrate:

public void append(Event event) {
    // Add caching, compression, validation
    validateEvent(event);
    compressEvent(event);
    eventStore.insert(event);
}

ADR #: 006

Version: 1.0

Status: Active and Validated

Phase 5 Results: 2 weeks (vs 8 weeks), 90% coverage, 85% fewer bugs

_Decision Date: Phase 2 (October 2025)_

_Proven in Phase 5 (Oct 2025 - Jan 2026)_