Onion Architecture Experts in Germany
matched in minutes with vetted, available freelance professionalsHire experts who design domain-centered systems, separate business rules from infrastructure, and guide migrations from tightly coupled applications to maintainable .NET, Java or other service architectures. Get precisely matched with vetted, available freelancers quickly.
Meet FRATCH Experts in Germany, who have recently used Onion Architecture
Jens H.
Last position:
Interim CTO (occasional assignments) at Fujitsu / FSAS
Stabilization of an Azure/.NET landscape in live operation.
- Architecture, DevOps, and operational readiness; technical decisions under time pressure
- Azure DevOps, monitoring, ETL/ELT, cloud security, FinOps, and data-mesh-related topics
Technologies: Azure DevOps, .NET, CI/CD, monitoring, FinOps
Giuseppe A.
Last position:
Embedded Software Development at Inheco
- AI Integration (LLM & RAG): Designed and built an internal intelligent RAG system (Retrieval-Augmented Generation) based on LLMs, n8n, and vector data to automatically analyze technical documents and error logs.
- Design & Implementation: Designed a robust RS-232/UART communication interface for an SBC-based embedded device used to control medical shaker systems.
- Architecture & Protocol Design: Built a highly maintainable software structure (OOP, SOLID) and defined resilient, hardware-level communication protocols, including multithreading and advanced error handling.
- Quality Assurance & DevOps: Automated testing with xUnit, ran integration tests directly on the hardware target, and maintained technical documentation to strict medical technology standards via Azure DevOps.
Label: C#, .NET, LLMs, RAG, n8n, RS-232, UART, Multithreading, async/await, xUnit, gRPC/protobuf, Blazor, MudBlazor, EF Core, Visual Studio 2026, Azure DevOps
Osman T.
Last position:
Senior Architect, DevOps Engineer at genPsoft GmbH
IT consulting, analysis, architecture design, new and further development, code review, test automation, continuous integration, continuous delivery in backend and frontend areas for Automotive Project Instavalo.
Frontend:
- Implementation of UI components according to specifications, especially style guides and responsive design eith React and Typescript
- Component testing
- Code documentation
- CI/CD with Gitlab Pipeline
Backend / IoT:
- Analysis and architectural design with AWS Greengrass IoT on Edge Devices
- Setting up Microservices containers with Docker Compose on Edge device with AWS Greengrass and AWS IoT IAM, Token Exchange Service, Ansible
- CI/CD with Gitlab Pipeline, Terraform, AWS ECR
- Logging with Fluentbit Lua Language for AWS Cloudwatch
- Python Lambda for AWS Greengrass Recipe deployment on Edge Devices
- Implementation of test-driven development with JUnit, Mockito, and code Coverage
- Jacoco
- Definition of REST interfaces with OpenAPI / Swagger
- Development and enhancement of software based on Java Quarkus, Typescript NestJs NodeJs and Python
- Authentication and authorization in Aws IAM
- Development of REST and gRPC interfaces for the frontend and backend
- Implementation of Maven dependencies with DevSecOps OWASP
- Spring AI, Jetbrains AI Assistant, Junie, Github Copilot, Claude Code, Agents, Skills, Command, Hooks, Subagents
Ibrahim H.
Last position:
Senior Full Stack / AI Engineer at Punktum Digital GmbH
- Context: Healthcare and laboratory teams required faster document analysis, treatment-planning support, and reliable AI workflows for MR/VR-assisted operations.
- Contribution: Built the AI healthcare platform, model/agent workflows, VR-glasses deployment platform, REST APIs, Next.js/React interfaces, and CI/CD pipelines.
- Impact: Delivered a production-ready AI product foundation that improved clinical document review, supported laboratory automation, and made VR fleet deployment manageable across environments.
Tech: TypeScript, Next.js, Node.js, React, Java, Spring Boot, Python, PyTorch, TensorFlow, Docker, PostgreSQL, OpenAPI, GitLab, GitHub Actions.
Hüseyin K.
Last position:
Senior Full-Stack Engineer at DVAG
Architecture and implementation of a fully digitalized closing flow for managing securities contracts within the DVAG infrastructure. The platform aims for maximum user-friendliness, modular extensibility and compliant handling of sensitive data.
Implementation of a reactive UI structure with a focus on user guidance & accessibility.
Dynamic control of form and closing processes including validation logic.
Reactive state management via SignalStore (signals + selective effects).
UX optimization through adaptive components and Playwright-based UI tests.
Backend modularization to connect existing sales and contract logic.
API stability and DTO design according to Clean Architecture principles.
Collaboration with domain teams to define technical contracts and service boundaries.
Management with GitHub.
Unit tests with Jest, E2E tests with Playwright.
Code reviews, CI-integrated test execution, iterative refactorings.
Ensuring high coverage and UI stability in the closing flow.
Technologies: Angular 18, RxJS, SignalStore, HTML5, SCSS, Spring Boot, Kotlin, REST, OAuth2, Jest, Playwright, Clean Architecture.
Hans-Peter M.
Last position:
Developer at IT Center of the Federal Employment Agency
- Developing event-driven microservices with REST controllers and services
- Mapping data with JSON models
- Producing and consuming Kafka streams
- Generating PDFs
- Developing smart components, services, guards
- Processing the REST stream using observables following the reactive programming paradigm
- Integrating web components
- Implementing user authentication using OIDC/OAuth2 and JWTs
- Integrating Keycloak for simplified identity provider connection and introducing two-factor authentication
- Creating mockups for planning, implementation analysis, and feasibility studies
- Analyzing and implementing business requirements
- Conducting code reviews
- Maintaining and updating CI/CD pipelines
- Performing refactorings
- Conducting sprint reviews
- Monitoring production applications via Kibana and Grafana
Discover over 15,000 top freelancers
Statistics of experts using Onion Architecture
Aggregated from the professional profiles of matched freelancers.
Experience
18 years
Position duration
1 year
Positions per freelancer
16
Top business areas
Information Technology, Product Development, Quality Assurance
Top industries
Information Technology, Automotive, Banking and Finance
Certification focus areas
Information Technology, Product Development
Bachelor's degree or higher
100%
Master's degree or higher
67%
Certifications per freelancer
3
Most common languages
German, English, Arabic
Speak two or more languages
100%
Based on our profile pool as of 29 Oct 2026.
Daily rate distribution
The chart shows how the daily rates of experts in this technology in Germany are distributed, based on recent contracts on our platform. Each bar covers a rate range — its height shows the share of experts charging within that range.
Average rates of experts in Germany using Onion Architecture
Rates are based on recent contracts and do not include FRATCH margin.
The average daily rate is the mean of all daily rates from recent contracts of comparable freelancers on our platform.
The median daily rate is the middle value of all daily rates — half of comparable freelancers charge less, half charge more. Unlike the average, it is barely affected by outliers.
Calculated based on our freelancers’ daily rates as of 29 Oct 2026. Actual rates may vary depending on seniority level, experience, skill specialization, project complexity, and engagement length.
Onion Architecture experts industry focus
See which industries our matched freelancers work in most often — every figure is calculated live from the freelancers on FRATCH.
- Information Technology (100%)
- Automotive (83%)
- Banking and Finance (67%)
- Healthcare (67%)
- Insurance (67%)
- Manufacturing (67%)
- Government and Administration (67%)
- Transportation (50%)
Please note that freelancers can work across multiple industries, so percentages overlap.
About the technology
Core principle
Onion Architecture places the domain model and business rules at the center of an application. Dependencies point inward, so the core does not depend on databases, web frameworks or external services. This keeps important rules easier to test, change and reuse.
What it builds
The approach suits business-critical applications with complex rules and long maintenance horizons. It is used for modular monoliths, APIs, transaction systems and service-oriented backends where clear boundaries matter.
- Domain models and application use cases
- REST or messaging interfaces around a stable core
- Adapters for persistence, payment and external services
- Incremental modernization of tightly coupled systems
Ecosystem and tooling
Onion Architecture is a design approach rather than a framework. Specialists commonly apply it with .NET, Java, Spring, ASP.NET Core, Node.js or other application stacks, using dependency injection, repository abstractions, automated tests and CI pipelines to enforce the intended boundaries.
When expertise helps
Companies usually bring in freelance expertise when a codebase has business logic scattered across controllers, database models and integrations. A specialist can define bounded responsibilities, choose practical project boundaries and migrate valuable functionality without stopping ongoing delivery.
- Reorganizing a legacy application around domain rules
- Reviewing dependencies and module boundaries
- Introducing testable use cases and ports
- Establishing architecture guidelines for a team
Strong professional practice
Strong professionals distinguish useful separation from unnecessary layers. They keep domain objects independent, make infrastructure replaceable and document decisions in terms the delivery team can use. They also understand transactions, data mapping, observability, security and deployment rather than treating architecture as diagrams alone.
Delivery in Germany
For teams in Germany, Onion Architecture can support complex products in manufacturing, finance, logistics, healthcare and public services. Remote collaboration works well when interfaces, decision records and review routines are clear; on-site workshops may help during discovery, migration planning or domain modelling. German or English communication should be agreed at the start.
Frequently asked questions
The facts hiring teams ask for most often when it comes to Onion Architecture.
Onion Architecture is used to organize applications around a domain core that contains business rules and use cases. It is especially useful when an application must remain testable and adaptable while databases, interfaces and third-party services change.
Onion Architecture and Clean Architecture both direct dependencies toward business rules and separate infrastructure from the core. Clean Architecture presents a broader set of concentric boundaries, while Onion Architecture is often explained through domain, application, infrastructure and presentation layers; the practical result depends on how consistently the team applies either approach.
Onion Architecture shares the main goal of Hexagonal Architecture: keeping the application core independent from external systems. Hexagonal design emphasizes ports and adapters, while Onion Architecture commonly emphasizes concentric layers and inward dependency flow. Many teams combine ideas from both.
A strong Onion Architecture specialist should understand domain-driven design, dependency injection, modularization and automated testing. Depending on the stack, useful adjacent skills include Spring, ASP.NET Core, relational data modelling, messaging, API design, observability and deployment automation.
A capable Onion Architecture professional should have applied the approach to a real application rather than only describing its layers. The right depth depends on the work: a boundary review may need focused architecture experience, while a legacy migration calls for hands-on delivery across domain modelling, testing, persistence and integration.
Onion Architecture work can be handled remotely when the team shares domain language, architecture decisions and review practices. German and English are both common working languages, but teams should clarify language expectations, workshop needs and any on-site collaboration before the engagement begins.
Ask how the Onion Architecture professional would protect domain rules from framework and database concerns in your specific system. Good answers address trade-offs, migration steps, testing boundaries, data ownership and operational needs instead of presenting layers as a universal template.
Onion Architecture may add needless ceremony to a small application with simple rules and a short lifespan. It can also fail when teams create empty layers, excessive abstractions or repositories without a clear domain purpose. A thoughtful professional first checks the system's complexity and change patterns.
The average hourly rate of freelancers in Germany who have used Onion Architecture in their recent projects is 91 €, which corresponds to a daily rate of about 729 € based on an 8-hour working day.
Of the freelancers in Germany who have used Onion Architecture in their recent projects, 100% hold at least a Bachelor's degree and 67% hold at least a Master's degree.
On average, freelancers in Germany who have used Onion Architecture in their recent projects have 18 years of professional experience, with a single engagement typically lasting around 1 year.
The most common languages among freelancers in Germany who have used Onion Architecture in their recent projects are German (100%), English (100%), and Arabic (33%).
The most common industries among freelancers in Germany who have used Onion Architecture in their recent projects are Information Technology (100%), Automotive (83%), and Banking and Finance (67%).
The most common business areas among freelancers in Germany who have used Onion Architecture in their recent projects are Information Technology (100%), Product Development (100%), and Quality Assurance (83%).
Main locations of FRATCH Experts, who have recently used Onion Architecture
Our freelancers and interim experts are at home across the DACH region — available on-site in the major business hubs or fully remote. Choose a location to discover matched specialists, local market insights and up-to-date availability.
Berlin Hamburg Munich Cologne Frankfurt Stuttgart Dusseldorf Leipzig Dortmund Essen Bremen Dresden Hanover Nuremberg Request a free demo
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Philipp Thomaschewski
FRATCH CEO
