Architecture Paradigm Service Based

---
name: architecture-paradigm-service-based
description: '- When teams require a degree of deployment independence but are not
  yet prepared for the complexity of managing numerous microservices.'
---

---
name: architecture-paradigm-service-based
description: |

Triggers: service-based, architecture, based, modular, service
  Coarse-grained service architecture for deployment independence without microservices complexity.

  Triggers: service-based, SOA, coarse-grained services, domain services
  Use when: teams need deployment independence without microservices complexity
  DO NOT use when: fine-grained scaling needed - use microservices.
version: 1.3.7
category: architectural-pattern
tags: [architecture, service-based, soa, modular, shared-database]
dependencies: []
tools: [api-gateway, service-registry, schema-management]
usage_patterns:
  - paradigm-implementation
  - monolith-refactoring
  - deployment-independence
complexity: medium
estimated_tokens: 700
---

# The Service-Based Architecture Paradigm

## When to Employ This Paradigm
- When teams require a degree of deployment independence but are not yet prepared for the complexity of managing numerous microservices.
- When shared databases or large-scale systems (like ERPs) make full service autonomy unrealistic.
- When establishing clear service contracts for partner teams or external consumers.

## Adoption Steps
1. **Group Capabilities**: Bundle related business functions into a small set of well-defined services, each with a designated owner.
2. **Define Service Contracts**: Publish formal specifications using standards like OpenAPI or AsyncAPI, including Service Level Agreements (SLAs) and a clear versioning strategy.
3. **Control Database Schemas**: Even when services share a database, assign explicit ownership for each schema or table. Gate all breaking changes through a formal review process.
4. **Establish Service Mediation**: Use a service registry or an API gateway to handle routing, authentication, and observability.
5. **Plan for Evolution**: Identify architectural "hotspots" that are likely candidates for being split into more granular services in the future.

## Key Deliverables
- An Architecture Decision Record (ADR) that outlines service boundaries, data ownership rules, and coordination mechanisms.
- A suite of contract tests and consumer-driven contract tests for each service to validate stability.
- Runbooks that describe deployment procedures, rollback plans, and service dependencies.

## Risks & Mitigations
- **Coupling Through a Shared Database**:
  - **Mitigation**: Changes to a shared database can have cascading effects across services. Mitigate this by using database views, replication, or a formal schema deprecation schedule to manage change.
- **Architectural Degradation**:
  - **Mitigation**: Without strong governance, this architecture can degrade into a "distributed monolith"—a monolith with the added complexity of network hops. Track coupling metrics closely and enforce strict ownership of services and data to prevent this.
## Troubleshooting

### Common Issues

**Command not found**
Ensure all dependencies are installed and in PATH

**Permission errors**
Check file permissions and run with appropriate privileges

**Unexpected behavior**
Enable verbose logging with `--verbose` flag