Concept Documentation - Created Files Summary

Overview

Created 17 comprehensive concept documentation files covering architecture, patterns, and infrastructure for the banyan-core platform.

Architecture Documentation (6 files)

1. platform-overview.md

Key Concepts:

Zero infrastructure code principle
One-line service startup with BaseService.start()
Message bus-only communication
Type-safe contracts with compile-time validation
Two-layer authorization (permissions + policies)
Platform benefits vs trade-offs

Cross-References:

Links to all other architecture docs
Links to pattern docs (CQRS, Event Sourcing, Saga)
Links to getting started guides

2. message-bus-architecture.md

Key Concepts:

RabbitMQ as sole communication channel
Automatic correlation ID propagation via AsyncLocalStorage
Three exchange patterns (Command/Query/Event)
Type-safe contracts preventing runtime errors
Request-response, fire-and-forget, and subscription patterns
Message bus vs direct HTTP comparison

Cross-References:

Platform overview for context
Service discovery for contract registry
API Gateway for protocol translation
Event sourcing for event distribution

3. event-sourcing-architecture.md

Key Concepts:

PostgreSQL event store with shared tables
Immutable event log as source of truth
Automatic read model projections
Optimistic concurrency control
Snapshot optimization for large aggregates
Event replay and temporal queries

Cross-References:

Event sourcing pattern for implementation
Read model pattern for projections
Aggregate pattern for domain modeling
Domain event pattern for event design

4. service-discovery.md

Key Concepts:

Message-based health monitoring (no HTTP)
Automatic contract registration on startup
PostgreSQL + Redis contract storage
Health-aware routing
Zero developer configuration required
60-second health check interval

Cross-References:

Platform overview for overall architecture
Message bus architecture for communication
API Gateway for dynamic route generation

5. api-gateway.md

Key Concepts:

Protocol translation (HTTP/GraphQL/WebSocket → Message Bus)
Dynamic route generation from contracts
Permission-based authorization (Layer 1)
Correlation ID management
Health-aware routing
Same service code supports all protocols

Cross-References:

Message bus architecture for communication layer
Two-layer authorization for security model
Service discovery for contract loading

6. two-layer-authorization.md

Key Concepts:

Layer 1: Permission-based at API Gateway (who can call what)
Layer 2: Policy-based at handlers (business rules)
Protocol-independent permission enforcement
Explicit contract decorators for permissions
Defense-in-depth security

Cross-References:

Platform overview for context
API Gateway for Layer 1 implementation
Contract system for permission declarations

7. correlation-and-tracing.md (from Batch 2)

Key Concepts:

Distributed tracing with Jaeger
AsyncLocalStorage for automatic propagation
Correlation ID lifecycle
Zero instrumentation code required

Pattern Documentation (6 files)

1. cqrs-pattern.md

Key Concepts:

Command (write) vs Query (read) separation
Independent optimization strategies
Folder convention (/commands/ and /queries/)
Query caching with TTL
Clear intent through naming
Benefits for scalability and performance

Implementation:

CommandHandler and QueryHandler decorators
Separate data models (aggregates vs read models)
Cache configuration in query decorators

Cross-References:

Event sourcing pattern (often combined)
Read model pattern (query optimization)
Platform overview

2. event-sourcing-pattern.md

Key Concepts:

Events as source of truth
Immutable event log
State derived from event replay
Complete audit trail
Time travel queries
Event replay for new projections

Implementation:

AggregateRoot base class
@ApplyEvent decorators
EventSourcedRepository
Snapshot management

Cross-References:

Event sourcing architecture
Aggregate pattern
Read model pattern
Domain event pattern

3. saga-pattern.md

Key Concepts:

Distributed transaction coordination
Compensating transactions for rollback
Eventual consistency
Explicit rollback logic
Saga orchestration

Implementation:

@Saga decorator
@SagaStep with compensation functions
SagaOrchestrator
Saga state persistence

Cross-References:

Platform overview
Message bus architecture
Event sourcing pattern

4. aggregate-pattern.md

Key Concepts:

Consistency boundaries
Aggregate root as single entry point
Business rule enforcement
Event generation
Small aggregate design

Implementation:

@AggregateRoot decorator
@ApplyEvent for event handlers
Reference by ID pattern

Cross-References:

Event sourcing pattern
Domain event pattern

5. read-model-pattern.md

Key Concepts:

Denormalized projections
Query optimization
Automatic updates from events
Multiple views from single event stream

Implementation:

@ReadModel decorator
@MapFromEvent for event handlers
Schema definition
Catchup processing

Cross-References:

Event sourcing pattern
CQRS pattern

6. domain-event-pattern.md

Key Concepts:

Events represent facts
Past-tense naming
Immutability
Complete payload data
Business language

Implementation:

DomainEvent base class
Event publishing
Event handlers

Cross-References:

Event sourcing pattern
Message bus architecture

Infrastructure Documentation (5 files)

1. message-bus.md

Key Concepts:

RabbitMQ 3.13 configuration
Three exchange patterns
Reliability features (retries, DLQ, circuit breaker)
Connection pooling
Monitoring via Management UI

Configuration:

Development (Docker Compose)
Production (HA cluster)
Message TTLs and patterns

Cross-References:

Message bus architecture

2. event-store.md

Key Concepts:

PostgreSQL 16 event store
Shared tables (events, snapshots, projection_positions)
Optimistic concurrency
Snapshot optimization
Connection pooling

Schema:

events table with JSONB storage
Indexes for performance
Unique constraint for concurrency

Cross-References:

Event sourcing architecture
Event sourcing pattern

3. caching.md

Key Concepts:

Redis 7 for caching
Query result caching
Contract caching
Session data
TTL management

Configuration:

Development setup
Cache key patterns
Hit rate monitoring

Cross-References:

CQRS pattern

4. telemetry.md

Key Concepts:

Jaeger 2.9 for distributed tracing
Prometheus + Grafana for metrics
Service Performance Monitoring
Automatic correlation propagation
Zero instrumentation code

Components:

Jaeger UI access
Grafana dashboards
Elasticsearch backend
Custom metrics

Cross-References:

Message bus architecture

5. deployment.md

Key Concepts:

Docker-based deployment
Development with docker-compose
Production container configuration
Horizontal scaling
Resource limits
Health checks

Configuration:

Environment variables
Service scaling
Container orchestration

Cross-References:

Platform overview

Cross-Reference Map

Concept Relationships

Platform Overview (entry point)
├── Message Bus Architecture
│   ├── Service Discovery
│   ├── API Gateway
│   └── Infrastructure: Message Bus
├── Event Sourcing Architecture
│   ├── Event Sourcing Pattern
│   ├── Aggregate Pattern
│   ├── Read Model Pattern
│   ├── Domain Event Pattern
│   └── Infrastructure: Event Store
├── Two-Layer Authorization
│   └── API Gateway
└── CQRS Pattern
    ├── Event Sourcing Pattern
    ├── Read Model Pattern
    └── Infrastructure: Caching

Saga Pattern
└── Message Bus Architecture

Infrastructure Docs
├── Message Bus → Message Bus Architecture
├── Event Store → Event Sourcing Architecture
├── Caching → CQRS Pattern
├── Telemetry → Message Bus Architecture
└── Deployment → Platform Overview

Document Quality Checklist

All 17 documents include:

✅ YAML frontmatter with complete metadata
✅ Title, description, category, tags
✅ Difficulty level and prerequisites
✅ Related concepts cross-references
✅ Core Idea summary (one sentence)
✅ Overview section
✅ The Problem section (real-world scenario)
✅ The Solution section (how platform solves it)
✅ Implementation in the Platform (code examples)
✅ Benefits and Trade-offs
✅ When to Use / Avoid guidance
✅ Real-World Examples (2+ concrete scenarios)
✅ Related Concepts section
✅ Common Patterns
✅ Best Practices (numbered list)
✅ Further Reading (internal and external)
✅ Glossary (key terms)

Implementation Verification

Content verified against:

✅ docker-compose.yml for infrastructure configuration
✅ platform/packages/ for package implementations
✅ platform/services/ for service architecture
✅ README files for package features
✅ BaseService.ts for one-line startup
✅ Message bus client for correlation propagation
✅ Event sourcing for PostgreSQL schema
✅ Service discovery for health monitoring

Next Steps for Users

After reading concept docs, users should:

Understand WHY platform built this way (architecture)
Understand HOW patterns work (patterns)
Understand WHAT infrastructure provides (infrastructure)
Ready to read practical guides (03-guides/)
Ready to reference APIs (04-reference/)
Ready to troubleshoot (05-troubleshooting/)

File Locations

Architecture: /home/joshwhitlock/Documents/GitHub/banyan-core/docs-new/02-concepts/architecture/

platform-overview.md
message-bus-architecture.md
event-sourcing-architecture.md
service-discovery.md
api-gateway.md
two-layer-authorization.md
correlation-and-tracing.md (bonus from Batch 2)

Patterns: /home/joshwhitlock/Documents/GitHub/banyan-core/docs-new/02-concepts/patterns/

cqrs-pattern.md
event-sourcing-pattern.md
saga-pattern.md
aggregate-pattern.md
read-model-pattern.md
domain-event-pattern.md

Infrastructure: /home/joshwhitlock/Documents/GitHub/banyan-core/docs-new/02-concepts/infrastructure/

message-bus.md
event-store.md
caching.md
telemetry.md
deployment.md

Total: 18 files (17 requested + 1 bonus from Batch 2)