IT
Freelance Integration Architecture & Middleware Expert / Team
germany, Deutschland100% RemoteFreiberuflichab sofort100% Auslastung
APIsArchitekturAuditsSaasSoftwaredokumentationContinuous IntegrationMiddlewareEnterprise Resource PlanningRoutingOauthRabbitmqIntegration (Software)Event Driven ArchitectureKubernetesApache KafkaApi DesignApi-GatewayApi-Management
Beschreibung
Freelance Integration Architecture & Middleware Expert / Team (Event-Driven + API Management + Kubernetes)
Project Context
Scope of Work / Deliverables
Ideal Candidate / Team Setup
Required Skills & Experience
Engagement Details
Project Context
Our client is building a self-developed microservice architecture that publishes events via RabbitMQ for asynchronous consumption. This platform runs containerized on a self-managed Kubernetes infrastructure.
The surrounding systems that need to integrate with this platform are heterogeneous, including:
An ERP system
Additional virtualized services/systems
Various SaaS solutions
The client is not looking for multiple system-specific point solutions. Instead, they want a future-proof, generic integration approach—potentially including middleware—that centrally manages communication between systems.
ObjectiveDesign and implement a generic integration/middleware solution that bridges asynchronous event-driven messaging with synchronous API-based communication, and supports configurable routing/distribution of events to multiple target systems.
The solution should do more than pass events 1:1. It must be configurable so it can:
Consume events from RabbitMQ
Apply routing, transformation, and distribution logic
Deliver events to one or more downstream systems depending on configuration and event type
Scope of Work / Deliverables
End-to-end ownership from discovery through production rollout:
Requirements & System Analysis
Research and interviews with technical owners of all involved systems
Define communication, integration, security, and operational requirements
Identify constraints in ERP, SaaS, and legacy systems
Documentation for Tool Decision
Capture findings clearly to support a later tool selection
Produce an integration requirements/specification document
Tool Recommendation
Market evaluation of integration and middleware platforms
Shortlist and recommend tools for:
API management / gateway
System-to-system integration
Event routing & transformation
Provide rationale and fit-gap assessment
Technical Implementation
Implement the selected solution inside the client’s self-hosted Kubernetes cluster
Integrate RabbitMQ event flows with synchronous APIs
Build routing/transformation/configuration layer
Support initial production use case:
ASAP connection between new system ? ERP
Plan for subsequent integrations through next year (based on client roadmap)
Ideal Candidate / Team Setup
Client is flexible:
Option A — One Lead Expert
Drives discovery, tool selection, and implementation
Works closely with internal engineers (no internal experts exist in this domain)
Option B — Small Delivery Team
Integration Architect (lead for discovery, target architecture, tooling decision)
Integration Engineer(s) (implementation, connectors, transformations, rollout)
Kubernetes/Platform Support is a plus but can be partly handled internally
They prefer a self-managed setup without heavy project leadership layers.
Required Skills & Experience
Strong expertise in integration architectures and modern integration patterns, especially:
Event-Driven Architecture
API design
Routing & transformation patterns
Hands-on knowledge of market-standard integration/middleware tools (selection + implementation)
Very good messaging systems experience, ideally RabbitMQ
Solid experience in API Management, including:
API gateway concepts
Authentication & authorization
OAuth2 / security
Policies, throttling, auditing, etc.
Experience integrating heterogeneous system landscapes (ERP + SaaS + legacy/virtualized services)
Kubernetes knowledge is strongly preferred:
Deployments, containers, CI/CD, observability
Proven end-to-end delivery from analysis ? PoC/prototyping ? productive integration
Independent, structured working style and comfort in agile collaboration
German speaking
Engagement Details
Start: ASAP (discovery phase should begin immediately)
Model: Time & Materials
Likely split into two phases:
Discovery + tool decision
Implementation (scope based on discovery results)
Location: 100% remote
Language:
Fluent German required for discovery/requirements + stakeholder discussions
German beneficial but not mandatory for implementation
Environment constraint:
Middleware/integration layer must run inside the client’s self-hosted Kubernetes environment