JUnit Experts in Dusseldorf
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Meet FRATCH Experts in Dusseldorf, who have recently used JUnit
Marijn S.
Last position:
Senior Software Engineer at Puls Security GmbH
Optimizing and acceleraÂtion of our Gitlab CI pipeline
Conceptual work for the PoC of the Zero Trust system
Extension of the policy-engine backend in Go
Extension of the policy-testing mechanism in Python
Architectural design of the PEP component of Zero Trust
Documentation of the product
Technologies: Zero Trust, Go, Python, Gitlab CI, Docker, JWT, Domain-Driven Design
Boris S.
Last position:
Generalist expert for software development at Mercor
- Training AI models, evaluating images and text UI/UX, turning the provided data into insights through OpenAI Feather as part of the machine learning workflow
Technologies: OpenAI Feather
Hassan A.
Last position:
DevOps & Observability Consultant at ALDI South (Albrecht's Discount)
- Supporting the DevOps team in Terraform-managed, multi-region AWS infrastructure to achieve environment parity.
- Developed end-to-end CI/CD pipelines using AWS CodePipeline, CodeBuild, and CodeDeploy, automating the build and deployment.
- Maintained pre- and post-deployment scripts to automate critical tasks such as database schema migrations and environment sanity checks.
- Implemented CI/CD flow specifically for hotfixes via separate Git branches, managing back-merge activities from feature branches to release branches to ensure code integrity through automated conflict resolution.
- Deployed a dedicated, lightweight sanity check application hosted cost-effectively on Azure Container Apps to run automated health and basic functional checks as a post-deployment activity triggered via pipeline.
- Investigated production incidents through code changes and AWS CloudWatch logs.
- Coordinated integration of Dynatrace APM and its APIs for monitoring purposes.
- Full stack QA strategist for a high-traffic e-commerce platform built on a layered architecture for the back-end testing of core platform services, especially the order management system in Zed and Glue layers.
- Managed automation activities, testing process, and refactoring practices.
- Responsible for framework migrations, setup, and training for new automation frameworks.
- Promoted a shift-left approach within the QA team and created the test concept.
- Participated in meetings with IT managers, business owners, product owners, and team members.
- Designed and implemented contract testing to validate API schema compatibility between the order management system and the Zed and Glue layers, reducing production-relevant breaking changes by approximately 3%.
- Led the migration to a multi-environment framework that enabled test execution across 4 country configurations from a single codebase.
- Integrated automated unit and functional tests directly into the GitLab CI/CD pipeline, reducing pipeline runtime by 32%.
- Coached and trained 5 QA engineers across Germany and Hungary in test automation, framework architecture, and best practices.
- Architected a layered backend test automation framework separating business logic, API request builders, and the database layer.
- Piloted AI-assisted testing with Playwright Agents, the Playwright MCP Server, and GitHub Copilot for automated test generation, execution, and self-healing Playwright scripts.
Marc S.
Last position:
Fullstack Developer at PLANT-MY-TREE
PLANT-MY-TREE®-per-order
The application enables Shopify merchants to automatically place tree-planting orders for every incoming order. By integrating ecological contributions directly into the purchase process, the manual effort for tracking and billing reforestation initiatives is eliminated. The system increases transparency for end customers through real-time visualizations of the ecological impact directly in the storefront. The architecture is based on a modular monolith with Spring Boot in the backend and an integrated React app inside the Shopify admin area. The solution uses webhooks to capture order data in an event-driven way and integrates the weclapp ERP system for automated monthly invoicing. An app proxy mechanism provides dynamic statistics such as CO2 compensation and planted trees without any performance loss for the merchant shop.
Tasks:
- Design of the modular software architecture based on Spring Modulith to ensure high maintainability
- Development of the event-driven business logic for evaluating Shopify orders via webhooks
- Implementation of automated invoicing by connecting the weclapp REST API
- Building the frontend using React Router and Shopify App Bridge for native integration
- Design of the database model and implementation of the persistence layer with JPA/Hibernate and Prisma
- Integration of internationalization processes for global use in the frontend and email communication
- Automation of deployment processes using Docker and GitLab CI/CD
Project skills: Java 25, Spring Boot, Spring Security, Spring Modulith, Hibernate, JPA, REST API, PostgreSQL, Maven, Liquibase, React, TypeScript, React Router, Vite, Node.js, Prisma, Zod, Docker, Docker Compose, GitLab CI/CD, Shopify CLI, Shopify App Bridge, Polaris, weclapp, i18next, Lombok, Vitest
Anupriya P.
Last position:
Senior Software Engineer at Telefonica Germany
(Maternity/Parental Leave: July 2023 – Aug 2024)
- Domain: Payment Domain | Client: Telefonica Germany
- Project: General Payment Service
The General Payment Service is responsible for processing of online payments via external payment service provider like Safer pay and PayPal
- Developed Design of Use (DOU) and interface contract documentation, ensuring clarity and compliance across system integrations
- Designed and delivered REST/SOAP web services with Spring Boot and Spring Data JPA, publishing Swagger contracts through WSO2 API Gateway to improve accessibility and governance.
- Spearheaded the on-premises to AWS Cloud migration, re-platforming from Oracle to PostgreSQL on AWS RDS and deploying services on EC2, improving scalability and cost efficiency.
- Containerized microservices using Docker and orchestrated deployments with Kubernetes, streamlining deployment pipelines and improving system reliability.
- Implemented proactive monitoring and logging via AWS CloudWatch and Kibana, ensuring stability and performance during cutover.
- Enhanced collaboration through code reviews and peer reviews, promoting maintainability and clean coding standards.
- Strengthened quality by writing comprehensive JUnit tests and preparing detailed test cases enabling early defect detection
- Delivered automated API testing with Ready API, Postman, and SOAPUI, and conducted performance testing with JMeter, ensuring reliability in high-transaction environments.
Jan G.
Last position:
Master Data Application at confidential
Visualization, search, and maintenance of various types of master data, providing them via a REST API, and implementing a variety of import and export formats.
Implementation, architecture, project management.
Technologies and tools: Angular (Signals, Signal Store, swagger-codegen, standalone components), Java, PostgreSQL, ActiveMQ, JavaScript, Spring Boot (Spring Core, Spring MVC, Spring Data/JPA via Hibernate, Spring Security, Spring Modulith), JUnit, Flyway, QueryDSL, GraphQL, REST API, Node, npm, Maven, SonarQube, GitLab CI/CD pipelines, Docker, Nexus, OpenAPI + Swagger UI, Keycloak, OAuth2, OpenID Connect, IntelliJ IDEA, Jira, Confluence.
Anouar T.
Last position:
Fullstack Developer Java/Spring Boot at Snipes SE (Deichmann Group)
- Migration of a .NET Core loyalty program for Snipes, used by mobile cash registers in Snipes stores
- Part of the customer’s digitalization strategy in an agile, cross-functional team with a high level of ownership
- Connecting interfaces to third-party systems (e.g. Brandung, CDS)
- Quality assurance through automated tests
- Carrying out developer, unit, and integration tests
- Patterns & methods used: Clean Code, microservice architecture, agile development with SCRUM
- Technologies & tools used: Spring Boot, Java 23, Java Persistence API (JPA), Azure DevOps, Azure Key Vault, Azure PostgreSQL, Docker & Kubernetes, Git, Graylog, Grafana, JUnit, SonarQube, Jira, Confluence, Prometheus, GitLab, GitLab CI/CD, Visual Studio Code
Rishu K.
Last position:
Java Technical Lead (Agile Developer) at Accenture
- Led the development of robust, scalable, and high-performance micro-services architecture.
- Migrated legacy monolith systems to Spring Boot with RESTful APIs.
- Designed, implemented, deployed, tested, and optimized scalable backend systems ensuring high availability and performance.
- Maintained and deployed Dockerized applications on Kubernetes integrated into CI/CD pipelines.
- Collaborated with cross-functional teams, including frontend developers, product managers, and designers, to translate business requirements into scalable and efficient backend solutions.
- Mentored team members and contributed meaningful code reviews.
Jacqueline H.
Last position:
Kitchen Appliance Manufacturer
Setting up and enhancing an international subscription management system
Migrating and decommissioning a Hybris-SAP system and integrating Zuora
Implementing numerous interfaces to various systems (external and internal)
Setting up and improving monitoring with Grafana, Prometheus, and Databricks
Introducing logging with Loki
Implementing business requirements using jQuery, Thymeleaf, Spring Boot, Java, Go, and Python
Adjusting and extending the GitLab CI pipelines
Setting up and extending infrastructure as code with Terraform and ArgoCD on AWS
Setting up and running E2E and performance tests
Expanding the Databricks business intelligence solution to provide various KPIs
Responsibilities: Architecture, DevOps, development, unit tests, coaching employees and apprentices, E2E, smoke, and integration tests, agile methods consulting (Kanban, Scrum)
Technologies and methods: Java, Go, Kotlin, Node.js, Spring Boot, SOAP/REST, Quarkus, Thymeleaf, Vaadin, Slack, Jira, Confluence, IntelliJ, GitLab, SQS, Kafka, AWS, Kubernetes, Terraform, Maven, Gradle, GitLab CI, Databricks
Discover over 15,000 top freelancers
Statistics of experts using JUnit
Aggregated from the professional profiles of matched freelancers.
Experience
13 years (Germany: 19 years)
Position duration
1.2 years (Germany: 1.9 years)
Positions per freelancer
11 (Germany: 13)
Top business areas
Information Technology, Product Development, Quality Assurance
Top industries
Information Technology, Banking and Finance, Retail
Certification focus areas
Information Technology, Project Management, Product Development
Bachelor's degree or higher
100% (Germany: 92%)
Master's degree or higher
43% (Germany: 51%)
Certifications per freelancer
12 (Germany: 2)
Most common languages
German, English, French
Speak two or more languages
100% (Germany: 96%)
Based on our profile pool as of 19 Sep 2026.
Daily rate distribution
The chart shows how the daily rates of freelancers in this technology in Dusseldorf are distributed, based on recent contracts on our platform. Each bar covers a rate range — its height shows how many freelancers charge within that range.
Average rates of experts in Dusseldorf using JUnit
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 19 Sep 2026. Actual rates may vary depending on seniority level, experience, skill specialization, project complexity, and engagement length.
JUnit 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%)
- Banking and Finance (67%)
- Retail (67%)
- Transportation (44%)
- Automotive (33%)
- Insurance (33%)
- Telecommunication (33%)
- Tourism (33%)
Please note that freelancers can work across multiple industries, so percentages overlap.
About the technology
What JUnit does
JUnit is the standard testing framework for Java applications. It helps teams verify classes, methods and business rules through repeatable automated tests before changes reach production. JUnit 5, also known as the JUnit Jupiter platform, supports modern test discovery and extension models while remaining compatible with established Java workflows.
Where it is used
JUnit tests sit inside many Java delivery processes, from Spring Boot services to large enterprise applications. Companies use them to check application logic, REST endpoints, persistence behaviour and integrations with external systems.
- Validate domain rules and service behaviour
- Test Spring components and web layers
- Cover repositories and database interactions
- Protect APIs during refactoring
- Run regression suites in continuous integration
Ecosystem and tooling
Strong JUnit work includes more than writing assertions. Experts work with Maven Surefire, Gradle test tasks, IntelliJ IDEA, Eclipse and CI systems such as Jenkins or GitHub Actions. They may also use Mockito for test doubles, AssertJ for readable assertions, Testcontainers for realistic dependencies and JaCoCo for coverage analysis.
JUnit 5 separates the platform, Jupiter programming model and Vintage support for older JUnit 4 tests. This structure gives teams a practical route to modernisation without forcing every test to change at once.
When companies need support
Freelance expertise is useful when a Java team has slow, fragile or misleading tests, or when a release depends on better automated coverage. It can also help during a migration, a Spring Boot upgrade, a service split or the introduction of a new CI pipeline.
- Stabilise flaky test suites
- Establish testing conventions for a growing team
- Modernise JUnit 4 tests with JUnit 5
- Add coverage around critical services
- Diagnose failures that appear only in CI
What strong experts deliver
Effective professionals design tests that explain expected behaviour and fail for useful reasons. They separate unit tests from integration and end-to-end checks, control external dependencies and keep test data understandable. Their deliverables may include test architecture, reusable fixtures, migration plans, CI configuration and clear documentation.
They also know when not to mock. Good judgement prevents brittle tests, excessive setup and coverage numbers that look healthy but miss important business risks.
Quality and collaboration
Assess a JUnit specialist through examples of test suites they have improved, not through test volume alone. Ask how they handle isolation, parameterised tests, exceptions, concurrency, time-dependent code and failures caused by shared state. A practical review should include build tooling and the way results are reported to the team.
For companies in Dusseldorf, remote collaboration works well when repository access, review standards and CI feedback are clear. On-site sessions can help with legacy systems or workshops, while English is common across international Java teams and German may matter for local stakeholders.
Frequently asked questions
Need clarity? These are the questions we hear most often about JUnit.
JUnit is used to automate tests for Java code, including classes, services, controllers and business rules. Teams run these tests during development and in continuous integration to detect regressions before release.
JUnit 5 introduces the Jupiter programming model, a more flexible extension system and a platform that can run different test engines. JUnit 4 remains common in older codebases, so migration often involves updating annotations, lifecycle methods, runners and build configuration.
A strong JUnit specialist usually understands Java, object-oriented design and build tools such as Maven or Gradle. Mockito, AssertJ, Spring Boot testing, Testcontainers and CI configuration are valuable adjacent skills.
The right level depends on the test suite and the risks involved, not on a fixed period of experience. A small feature may need someone comfortable with unit tests, while a legacy migration or distributed system benefits from a professional who can shape test strategy, tooling and team practices.
Yes, JUnit work is well suited to remote collaboration because tests, build files and CI results are shared through the code repository. Clear review rules, reliable environments and agreed communication in English or German help avoid misunderstandings.
Look for tests that are isolated, readable, repeatable and focused on meaningful behaviour. A capable JUnit professional can explain why a test is a unit, integration or end-to-end check and can show how failures lead to a useful diagnosis.
JUnit provides the test structure and execution model, but additional tools are often needed for realistic integrations. Teams may combine it with Spring Boot test support, Testcontainers, REST clients or browser automation, depending on the system boundary being tested.
A JUnit 4 migration requires attention to runners, rules, lifecycle annotations, assumptions and custom extensions. Professionals should assess build plugins and third-party integrations first, then use Jupiter and Vintage support to move the suite in controlled stages.
The average hourly rate of freelancers in Dusseldorf, Germany who have used JUnit in their recent projects is 77 €, which corresponds to a daily rate of about 617 € based on an 8-hour working day.
Of the freelancers in Dusseldorf, Germany who have used JUnit in their recent projects, 100% hold at least a Bachelor's degree and 43% hold at least a Master's degree.
On average, freelancers in Dusseldorf, Germany who have used JUnit in their recent projects have 13 years of professional experience, with a single engagement typically lasting around 1.2 years.
The most common languages among freelancers in Dusseldorf, Germany who have used JUnit in their recent projects are German (100%), English (100%), and French (22%).
The most common industries among freelancers in Dusseldorf, Germany who have used JUnit in their recent projects are Information Technology (100%), Banking and Finance (67%), and Retail (67%).
The most common business areas among freelancers in Dusseldorf, Germany who have used JUnit in their recent projects are Information Technology (100%), Product Development (89%), and Quality Assurance (78%).
Main locations of FRATCH Experts, who have recently used JUnit
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.
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Philipp Thomaschewski
FRATCH CEO
