Catalog
concept#Integration#Architecture#Platform#Security

API Integration

Concept for connecting applications and services via defined interfaces to automate and coordinate data and process flows.

API integration connects heterogeneous applications, microservices, and data sources through well-defined interfaces and protocols to automate and synchronize data and business process flows.
Established
Medium

Classification

  • Medium
  • Technical
  • Architectural
  • Intermediate

Technical context

REST/HTTP APIsMessage brokers (e.g. Kafka)API gateways and service mesh

Principles & goals

Treat interfaces as contracts and version themPrioritize security and authentication in integrationImplement robust error and retry strategies
Build
Enterprise, Domain, Team

Use cases & scenarios

Compromises

  • Insufficient authentication leads to security incidents
  • Lack of observability complicates fault diagnosis
  • Tight coupling increases failure impacts
  • Define contracts early and extend backwards-compatible
  • Centralize authentication and rate limiting via gateway
  • Use standardized error codes and observability events

I/O & resources

  • API specification (e.g. OpenAPI)
  • Security and authentication information
  • Data mapping and transformation rules
  • Stable API contracts and endpoints
  • Monitoring and audit information
  • Reusable integration components

Description

API integration connects heterogeneous applications, microservices, and data sources through well-defined interfaces and protocols to automate and synchronize data and business process flows. It includes API design, authentication, mapping, orchestration, monitoring, versioning and error handling. Proper integrations increase reusability, scalability and operational reliability.

✔

  • Increased reusability of services
  • Better scalability through decoupled components
  • Improved operational visibility and monitoring

✖

  • Complexity in mapping heterogeneous data formats
  • Management of versioning and backward compatibility
  • Dependencies on third-party APIs and limits

  • Throughput (requests/s)

    Number of API calls processed per second; important for scaling.

  • Error rate

    Percentage of failed calls; indicator of stability.

  • Latency (P95/P99)

    Response time distributions to assess performance and SLAs.

REST API as an integration layer

Standardized REST interfaces with OpenAPI specification to unify different services.

Event-driven integration with webhooks

Events are delivered via webhooks to subscribed systems to enable near-real-time synchronization.

API gateway for routing and security

Use of an API gateway for centralized authentication, rate limiting and monitoring.

1

Capture requirements and integration scenarios

2

Define and version API contracts with OpenAPI

3

Implement authentication and authorization layer

4

Implement mapping, transformation and error logic

5

Establish monitoring, tests and rollout strategy

⚠️ Technical debt & bottlenecks

  • Ad-hoc mappings without tests
  • Tight coupling to legacy endpoints
  • Missing versioning policies
Network latencyRate limits of external servicesI/O and mapping performance
  • Synchronous blocking external API call in user thread
  • Exposing sensitive data without proper access controls
  • No documentation of expected data formats
  • Underestimating versioning effort
  • Ignoring rate limits of external services
  • Poor observability complicates operations
API design and specification (OpenAPI)Network, security and authentication knowledgeExperience with integration patterns and fault tolerance
ScalabilitySecurity and access controlOperability and observability
  • • Compatibility with legacy systems
  • • Compliance with data protection and regulatory requirements
  • • Network and infrastructure restrictions