Engineering

Status: Canonical section
Last updated: 2026-07-05

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Purpose

This section defines how ZAIXOS engineers build software — philosophy, principles, patterns, and workflows. It is the engineering counterpart to ARCHITECTURE/ (what the system is).

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Section map

Document	Topic
philosophy.md	Engineering philosophy
architecture-principles.md	Non-negotiable architecture rules
coding-principles.md	Code quality and style
ddd-rules.md	Domain-Driven Design layers
cqrs-rules.md	Commands vs queries
dto-rules.md	DTO-first contracts
contract-rules.md	Public contract surfaces
adapter-rules.md	Adapter and integration patterns
repository-rules.md	Persistence boundaries
testing-philosophy.md	Test pyramid and gates
ai-philosophy.md	AI engineering principles
documentation-standards.md	How we write docs
versioning.md	Semver and compatibility
release-workflow.md	Release process
review-workflow.md	Code and architecture review
onboarding.md	New engineer path

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Core philosophy (summary)

flowchart LR
    DOC[Documentation First] --> CON[Contracts First]
    CON --> VAL[Validation First]
    VAL --> IMP[Implementation]
    IMP --> FREEZE[Freeze & ADR]

1. No business logic in presentation — Controllers, Filament, Blade, Form Requests are thin
2. Module isolation — Cross-module access via contracts and events only
3. DTO-first public APIs — Never expose Eloquent across boundaries
4. Additive extension — Extend platforms and modules; do not rewrite frozen layers
5. AI is platform-owned — Products host presentation; PL-003 executes; PL-004 learns

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Legacy ERP entry points

Document	Role
development/ENGINEERING_INDEX.md	Historical ERP asset map
development/AI_DEVELOPMENT_ENVIRONMENT.md	EOS / AI development environment
developer-guide.md	ZEP developer onboarding

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Related

• ARCHITECTURE/README.md
• STANDARDS/README.md
• TUTORIALS/README.md
• GOVERNANCE/README.md

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