Enterprise Architecture

Integration Architecture & API Design

How Clavon designs integrations that are explicitly contracted, loosely coupled, observable, and built to evolve — rather than brittle connections that become liabilities.

The Problem

Why Integration Failures Are Silent and Expensive

Integration problems rarely cause a visible crash. They propagate silently — through coupled deployments, unclear ownership, and undocumented contracts — until they become exponentially expensive to fix.

Undocumented or unstable contracts between systems
Tight coupling disguised as convenience
Unclear data ownership — multiple systems write the same records
Synchronous call chains without failure isolation
Versioning handled informally — breaking changes silently deployed
Security bolted on after exposure rather than designed in
Principles

Six Non-Negotiable Integration Principles

Explicit Contracts Over Implicit Behavior
Ownership Before Connectivity
Loose Coupling Over Convenience
Failure Is Inevitable — Design for It
Backward Compatibility Is a Business Requirement
Observability Is Mandatory
Interaction Taxonomy

Three Interaction Types — Each Has Different Rules

Before designing an integration, Clavon classifies the interaction type. Commands, queries, and events have fundamentally different requirements for ownership, error handling, and coupling.

Commands

Intent to change state — directed at a specific owner

Queries

Read-only — no side effects, cacheable

Events

Fact that something happened — no assumed consumers

API Design

Five API Design Standards — Non-Negotiable

Clavon treats APIs as products with owners, lifecycles, and contracts. These five standards apply to every API — internal or external.

01

API as a Product

A named owner
Documented consumers
A versioning strategy
Lifecycle status (active, deprecated, retired)

APIs without ownership are operational liabilities.

02

Contract-First Design

Define request/response schemas before building
Document error semantics
Agree on versioning rules
Define performance expectations

Contracts are reviewed like code.

03

Versioning Strategy

URI-based or header-based (context-dependent)
Backward-compatible changes only within a version
Breaking changes require a new version

Anti-pattern: "We'll coordinate consumers informally."

04

Error Handling & Semantics

Use consistent status codes
Return machine-readable error structures
Separate user-facing from internal errors
Never leak sensitive information

Errors are part of the contract, not an afterthought.

05

Idempotency & Safety

Support idempotency where applicable
Tolerate retries without duplicate side effects
State mutation is explicit and audited

Non-negotiable in distributed systems.

API vs Event Decision

When to Use API vs Event

Immediate response requiredAPI
Loose coupling desiredEvent
High fan-out to many consumersEvent
User-driven actionAPI
Audit trail requiredEvent
Transactional consistency requiredAPI (carefully)
Asynchronous Integration

Events Are Contracts — Not Notifications

When to use async:

Decoupling producers and consumers across domains
High-throughput systems with variable consumer speed
Integration across organizational boundaries
Auditability and event reconstruction requirements

Event design non-negotiables:

Immutable — facts, not instructions
Factual naming: "OrderCreated" not "CreateOrder"
Owned by the producing domain
Versioned and schema-governed

Failure modes to avoid:

Undocumented event payloads consumed by surprise
Consumers depending on internal fields — hidden coupling
No replay strategy — events are lost on consumer failure
Silent schema drift — payloads change without notification
Integration Patterns

Standard Integration Patterns

Clavon recommends a small set of integration patterns — chosen for their reliability, auditability, and long-term maintainability.

API Gateway

North–south traffic, external-facing

Internal service mesh

East–west service-to-service communication

Event backbone

Cross-domain propagation and replay

Adapter layers

Legacy system integration with isolation

Security requirements per boundary:

Authentication mechanism per boundary
Authorization scope and least-privilege
Token lifetime and rotation policy
Service-to-service trust model
Audit logging of all access
Observability

Integration Observability Is Non-Optional

Structured logs with correlation IDs
Latency metrics and percentile tracking
Error rates per integration point
Retry and circuit-breaker events
Anti-Patterns

Integration Anti-Patterns

Shared databases across services — tight coupling masked as convenience
Hidden coupling through payload assumptions — fragile contracts
Versionless APIs — every change is a breaking change
Fire-and-forget integrations without monitoring
"Temporary" adapters with no retirement plan — permanent tech debt
What We Deliver

Deliverables

Integration architecture blueprint
API design standards and templates
Versioning and deprecation policy
Event schema governance model
Security and access patterns
Testing and observability requirements
Integration evolution roadmap
Related Services

Works Best Alongside

Enterprise Architecture & Systems Integration
Cloud & DevOps
QA & Test Automation
Architecture Patterns
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Design Integrations That Scale and Stay Maintainable

Clavon designs integration architectures that are explicit, observable, and built to evolve — not ad hoc connections that become operational risk.