JUnit Experts in Dusseldorf
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Meet FRATCH Experts in Dusseldorf, who have recently used JUnit
Marijn Scholtens
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 Solos
Last position:
Generalist expert for software development at Mercor
- Training the AI models, evaluating images and texts for UI/UX, turning the provided data into insights via OpenAI Feather as part of the machine learning workflow
Technologies: OpenAI Feather
Marc Smyk
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
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 Taoussi
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 Kumari
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 Haefke
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
0.9 years (Germany: 1.9 years)
Positions per freelancer
12 (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: 91%)
Master's degree or higher
40% (Germany: 54%)
Certifications per freelancer
15 (Germany: 3)
Most common languages
German, English, French
Speak two or more languages
100% (Germany: 96%)
Based on our profile pool as of 30 Aug 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 30 Aug 2026. Actual rates may vary depending on seniority level, experience, skill specialization, project complexity, and engagement length.
About the technology
What JUnit does
JUnit is the standard testing framework for Java projects. It helps experts write unit and integration tests that check business rules, edge cases, and regressions before code reaches production. Teams use it to keep service layers, libraries, and Spring-based systems stable.
Where it fits
- Test Java classes and methods
- Validate services, repositories, and APIs
- Run tests in CI pipelines
- Support refactoring without breaking behavior
JUnit often sits beside Mockito, Hamcrest, AssertJ, and build tools like Maven or Gradle. In Dusseldorf, it is common in enterprise Java environments, especially where teams need clear test coverage and disciplined release cycles.
What strong experts bring
Strong JUnit specialists do more than write assertions. They design tests that are readable, isolated, and easy to maintain. They know when to use JUnit 5 features such as parameterized tests, nested tests, and extension support instead of repeating fragile test code.
When companies bring them in
Companies hire freelance JUnit experts when tests are missing, slow, or hard to trust. That includes legacy Java code, a migration from JUnit 4 to JUnit Jupiter, or a build that fails because of unstable test suites. They also help teams review quality before a release or a larger refactor.
Ecosystem and skills
A good JUnit expert understands the full testing stack around Java. That includes mocking, fixture design, test data setup, build configuration, and code review habits that keep tests useful over time. They should also work well with Spring Test, Testcontainers, and CI tools.
How work usually looks
- Add missing tests for new Java features
- Stabilize brittle tests and remove duplication
- Migrate older JUnit 4 suites to JUnit 5
- Review test strategy for backend services
- Support remote or on-site collaboration in Dusseldorf
For companies, the value is clear: better release confidence and less rework. For freelancers, the work is usually close to the codebase, the build, and the team’s review process, so clear communication matters as much as framework knowledge.
Frequently asked questions
Need clarity? These are the questions we hear most often about JUnit.
JUnit is used to write and run automated tests for Java code. It helps teams check that classes, services, and business rules behave as expected before changes go live. Strong use of it usually means faster refactoring and fewer surprises in production.
JUnit is still the default choice in many Java codebases, especially when teams want a simple, well-supported test framework. TestNG can fit some test-heavy or highly configured setups, but JUnit 5 is often preferred for its modern API and broad ecosystem support. The better choice depends on the existing stack and how the team writes tests.
Start with the current test pain points: missing coverage, slow builds, flaky tests, or a migration from JUnit 4 to JUnit Jupiter. Ask which parts of the codebase need the most attention and whether the expert should work with Mockito, Spring Test, or CI pipelines. That gives you a clear scope before work starts.
A strong JUnit specialist usually knows mocking, assertion libraries, and Java build tools. In practice, that often means Mockito, AssertJ, Hamcrest, Maven, Gradle, and sometimes Testcontainers or Spring Boot testing support. Those skills make the tests more reliable and easier to maintain.
Simple test writing can be handled quickly, but legacy suites, fragile builds, and framework migrations need deeper experience. JUnit 5 knowledge matters when you want cleaner test structure, parameterized tests, or extension-based setup. The more business-critical the code, the more you want someone who has fixed real test problems before.
Yes. JUnit work is usually code-centric, so remote collaboration is often a good fit as long as the team shares a clear branch, review, and CI process. On-site time in Dusseldorf can still help when the expert needs to pair with the team on a legacy test suite or release issue.
Look for tests that are clear, isolated, and easy to change when the code changes. A solid JUnit expert explains why a test exists, avoids brittle setup, and reduces duplicate logic. Good signs are readable test names, stable CI runs, and sensible coverage of important business paths.
JUnit 4 is the older branch that many Java systems still use, while JUnit 5 is the newer platform with a more flexible design. JUnit Jupiter is the programming model inside JUnit 5, so when people say they need JUnit 5 support, they often mean Jupiter features, extensions, and modern annotations. A freelancer who understands the differences can migrate suites without breaking the build.
The average hourly rate of freelancers in Dusseldorf, Germany who have used JUnit in their recent projects is 81 €, which corresponds to a daily rate of about 646 € 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 40% 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 0.9 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 (29%).
The most common industries among freelancers in Dusseldorf, Germany who have used JUnit in their recent projects are Information Technology (100%), Banking and Finance (71%), and Retail (71%).
The most common business areas among freelancers in Dusseldorf, Germany who have used JUnit in their recent projects are Information Technology (100%), Product Development (100%), and Quality Assurance (71%).
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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Hamburg 
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Stuttgart 
Nuremberg Request a free demo
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Philipp Thomaschewski
FRATCH CEO
