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Agent 5: Builder Fleet ​

Blueprint → Working Software

Role ​

The Builder Fleet is not a single agent — it's a coordinated swarm of coding agents that construct the greenfield application in parallel. Backend, frontend, database, integrations, CI/CD, documentation — all built simultaneously from the architectural blueprint.

This is the stage where the Phoenix rises. No legacy code is referenced. No old patterns are preserved. The Builder Fleet constructs a modern system from a modern blueprint, using modern tools and patterns.


Inputs ​

  • System architecture and tech stack (Agent 4)
  • API contracts and data schema (Agent 4)
  • Build plan and sequencing (Agent 4)
  • Unified requirements specification (for business rule implementation)

Outputs ​

Production Codebase ​

A complete, working application:

  • Clean, well-structured source code following modern patterns
  • Comprehensive inline documentation
  • Unit tests for every business rule
  • Integration tests for every API endpoint
  • End-to-end tests for critical user journeys

Deployment Pipeline ​

Fully automated CI/CD:

  • Build, test, and deploy on every commit
  • Staging environment for validation
  • Production deployment with rollback capability
  • Environment-specific configuration management

Documentation ​

  • API documentation (auto-generated from OpenAPI specs)
  • Developer onboarding guide
  • Architecture decision records (ADRs)
  • Operational runbook (monitoring, alerting, incident response)

Infrastructure-as-Code ​

Everything needed to provision and run the application:

  • Container definitions (Dockerfile, docker-compose)
  • Orchestration configuration (Kubernetes manifests or equivalent)
  • Cloud resource definitions (Terraform, CloudFormation, or equivalent)
  • Monitoring and alerting setup

How the Fleet Works ​

Parallel Construction ​

The Builder Fleet divides the build plan into independent work streams that execute simultaneously:

Stream 1: Database schema + migrations + seed data
Stream 2: Backend services + API implementation
Stream 3: Frontend application + component library
Stream 4: Authentication + authorization
Stream 5: Integration adapters (external APIs, file transfers)
Stream 6: CI/CD pipeline + infrastructure
Stream 7: Test suites (unit, integration, e2e)

Each stream follows the same pattern:

  1. Read the relevant section of the blueprint
  2. Implement the specified behavior
  3. Write tests that validate the implementation against business rules
  4. Produce documentation

Coordination Protocol ​

Streams that share boundaries (e.g., frontend needs API contracts from backend) coordinate through the architectural blueprint — the contracts are defined before building begins, so each stream builds to the same specification.

Quality Enforcement ​

Every line of code produced by the Builder Fleet must:

  • Pass linting and formatting checks
  • Have corresponding test coverage
  • Trace back to a specific requirement in the unified spec
  • Follow the patterns established in the architectural blueprint

What the Builder Fleet Doesn't Do ​

  • Reference legacy code — the fleet builds from the blueprint, never from the old codebase
  • Make architectural decisions — those were made by Agent 4 and approved at the gate
  • Interpret business rules — the rules are already extracted, synthesized, and specified
  • Compromise on quality — no shortcuts, no "we'll fix it later," no technical debt

Human Validation Gate ​

Before passing to validation, the AI Software Lead:

  • Reviews critical code paths (business rule implementations, security boundaries)
  • Confirms the build matches the architectural blueprint
  • Verifies test coverage meets the defined threshold
  • Validates that the deployment pipeline works end-to-end
  • Spot-checks documentation quality

Next: Agent 6 — Validator & Certifier →