Station

Solution & Interface Design

Design the interface contract and interaction model for the selected implementation style.

Once the architecture pattern is known, the design must turn capability requirements into clear interface contracts, interactions, schemas, data rules, lifecycle expectations, and consumer obligations.

Method map

Metro map

Select a cycle, station, or stakeholder to open its permanent method page.

StrategicGovernanceConsumerTechnicalUser ExperienceUser ExperienceMarket InsightsMarket InsightsBusiness GoalsBusiness GoalsCompetitive AnalysisCompetitive AnalysisEcosystem VisionEcosystem VisionScalable InfrastructureScalable InfrastructureLegal and ComplianceLegal and ComplianceSecurity and PrivacySecurity and PrivacyDesign StandardsDesign StandardsVendor ManagementVendor ManagementContract DesignContract DesignDevelopmentDevelopmentCI/CDCI/CDTest AutomationTest AutomationRelease ManagementRelease ManagementService AgreementsService AgreementsConsumer AdoptionConsumer AdoptionPromotionPromotionPartner IntegrationPartner IntegrationAPI MindsetAPI MindsetRoles and ResponsibilitiesRoles and ResponsibilitiesUpskillingUpskillingOperating GuidelinesOperating GuidelinesPortfolio ManagementPortfolio ManagementBudget and Resource ManagementBudget and Resource ManagementStrategy1Capability StrategyConsumer Requirements & Onboarding2Consumer Requirements &OnboardingArchitecture & Platform Decisions3Architecture & PlatformDecisionsSolution & Interface Design4Solution & InterfaceDesignDelivery & Operations5Delivery & OperationsQuality & Readiness Assurance6Quality & ReadinessAssurancePublishing & Enablement7Publishing & EnablementMonitoring & Improvement8Monitoring & ImprovementBusiness Opportunities LinePlatform Architecture LineDesign LineDelivery LinePublishing and Adoption LineOperating Model Line

Selected station: Solution & Interface Design

People to involve

Related resources

Outcomes

  • A validated interface contract for the selected implementation style
  • Consistent interaction, data, event, file, workflow, or API contract decisions
  • Design traceability back to capability and consumer requirements
  • Designs aligned with domain models and interaction patterns

Journey criteria

Entry criteria

  • The capability addresses a clear business need and is reusable by its intended consumers.
  • The selected interface provides an appropriate abstraction for consumers.
  • The capability value proposition has been validated with business and consumer stakeholders.
  • Consumer segments are identified.
  • A high-level implementation roadmap is defined.

Exit criteria

  • The chosen architecture, platform, and implementation style have been validated with the relevant architecture, security, and platform stakeholders.
  • The selected interface provides an appropriate abstraction for consumers.
  • The interface design and exposed capabilities trace back to business value and consumer needs.
  • The interface design follows agreed design standards and conventions.

This is what success looks like

Select the design resources that fit the chosen implementation style and document the interface contract before implementation.

  1. Reuse the Domain Canvas to confirm business objects, terms, rules, and ownership before contract design. — Domain Canvas
  2. Use the Interaction Canvas to describe how consumers, systems, or users interact with the capability. — Interaction Canvas
  3. Use REST design resources when the selected interface is a REST API. — REST Canvas
  4. Use Event Canvas resources when the selected interface is event-driven. — Event Canvas
  5. Use GraphQL design resources when the selected interface is GraphQL.
  6. Use the design principles and style guidance to align design decisions with shared rules and enable consistent audit validation. — API Design Principles
  7. Apply contract-first or design-first approaches to capture and validate the interface contract before implementation.
  8. Use the audit checklist to ensure the design meets functional and non-functional requirements, including security, performance, and compliance. — API Audit Checklist

Metro lines

Design Line

Focuses on solution and interface design principles that can be used across APIs, integrations, automations, data products, and other implementation styles.

Review station resources

Browse the resources selected for Solution & Interface Design; the summary above explains how they support this station’s work.

Station resources

Resources for Solution & Interface Design

canvas

Interaction Canvas

Define interactions, workflows, inputs, outputs, commands, queries, events, and expected responses to ensure a consistent consumer experience.

Outcomes

  • Defined interaction model for the selected capability
  • Inputs, outputs, commands, queries, events, and responses clarified
  • Validation rules and interaction expectations agreed

How it works

  1. Map interactions to user, consumer, or system tasks
  2. Define access points, operations, commands, queries, or events for each interaction
  3. Document inputs and outputs for each interaction.
  4. Specify validation rules and constraints
  5. Create interaction models for CRUD, query-driven, command-driven, and event-driven interactions

Relevant cycles

API Productization Cycle

The API-focused APIOps Cycles journey for productizing, designing, delivering, publishing, and improving APIs.

Automation Cycle

A cycle for identifying, designing, delivering, enabling, and improving automation opportunities.