Jest Expert in Frankfurt
for reliable test suites, matched in minutes with vetted and available freelancersHire experts who create maintainable JavaScript and TypeScript tests, configure Jest with React and Node.js, and improve coverage in CI pipelines. Get fast, precise matching with vetted, available freelancers for remote or on-site work in Frankfurt.
Meet FRATCH Experts in Frankfurt, who have recently used Jest
Patrick L.
Last position:
Senior GenAI Fullstack Developer at SBH (Schulbau Hamburg)
Remote freelance role focused on Agentic AI strategy, secure application patterns, and reusable agentic workflows for a government agency.
- Development and implementation of an open source Agentic AI strategy for a government agency, with a focus on GDPR, security, and self hosted solutions
- Development of reusable agentic workflows and mini applications that enable non technical employees to solve business problems independently
- Implementation of internal business applications with Single Sign On (SSO) and Azure PostgreSQL integration on Hetzner Linux servers
- Implementation of nine mini applications with Single Sign On (SSO) and Azure PostgreSQL integration on Hetzner Linux servers
- Techstack: Python, Nextjs, Typescript, Streamlit, Anthropic SDK (Claude), Azure, Linux Ubuntu, PostgreSQL, MS SQL, Angular, Authentik
Michael H.
Last position:
Frontend Developer at RTL Tech
- Development and optimization of the RTL+ frontend application for SmartTV and set-top box platforms with React and Next.js.
- Key role in the technical coordination of developers within the team and in coordinating implementation.
- Central interface to adjacent teams to simplify development processes and improve cross-team alignment.
- Improved frontend performance, stability, and rendering behavior on low-powered devices in a restricted runtime environment.
- Implemented a frontend testing strategy with Jest, React Testing Library, and Playwright.
- Implemented accessibility improvements according to WCAG 2.2 and WAI-ARIA.
- Integrated Didomi Consent Management as a contribution to increasing ad monetization on streaming platforms.
- Used AI-supported engineering workflows with Cursor for structured implementation, refactoring, and faster problem solving.
Technologies used: React, Next.js, TypeScript, JavaScript, GraphQL, Apollo Gateway, Zustand, Tailwind CSS, Styled Components, React Testing Library, Playwright, Jest, HTML5, CSS3, AWS Lambda, EC2, CloudFront, S3, GitLab CI/CD, NX, Cursor
Uday V.
Last position:
Senior Full Stack Java Developer & DevOps Engineer at Deutsche Börse (DBAG)
Project: SCS (Settlement / Clearing Services)
Settlement platform serving multiple trading and clearing venues — counterparty risk safeguarding, settlement volume reduction, central risk management, and post-trade anonymity.
Technologies: Java 17, Spring Boot 3, Microservices, Spring Data JPA, SonarQube, Fortify (SCST), Mockito, Jenkins, OpenShift, Maven, Podman, GitHub, JIRA, Liquibase, Swagger, AMQP, Apache Camel, Terraform, PostgreSQL, Instana, Graylog.
- Identified and remediated CVEs in third-party libraries using SCA tooling, strengthening the security posture of production components.
- Maintained 90% code coverage with SonarQube, improving code quality and reducing production defects.
- Enabled mTLS for database authentication and message broker connections, enforcing encrypted, certificate-validated communication.
- Designed and deployed microservices with asynchronous, REST-based communication between components.
- Optimized a high-volume REST API (~200K requests) by reducing response time from 3s to 2s (33% improvement), boosting throughput and reliability under production load.
- Automated build and continuous integration pipelines using Maven and Jenkins.
- Orchestrated containerized workloads on Podman/OpenShift and governed schema evolution with Liquibase, ensuring reliable, repeatable deployments across all environments.
- Optimized Java code and implemented EHCache-based caching, improving application performance.
- Streamlined release management by governing application images, JAR versions, and dependencies through DBAG Artifactory, ensuring version consistency and audit traceability across environments
Werner K.
Last position:
Test Coordinator, Designer and Engineer at IBM
- Testing the SekIDP and related components
- Test design, execution and automation, microservices, GitHub Enterprise, Eclipse, Katalon Test Platform, API Testing, Confluence 8, JIRA/Xray, Draw.io, Swagger/OpenAPI, Postman, Docker, Kubernetes, Podman, PuTTY, E-Health, Telematik, Gematik standards, EPA, E-Rezept, sektoraler IDP, encryption, XaDES, PaDES, DICOM, HL7, FHIR, IHE, ICD, SSO, SAML/Shibboleth, OAuth, smartcards, JWT, two factor authentication Android and iOS, Wireshark, BrowserStack, Cypress, gRPC, REST, SOAP, WS-Security, Linux Shell, PowerShell, SSH/SSL, Java, Kotlin, Cordova, Gradle, Groovy, Python, TypeScript
Karsten G.
Last position:
Software Development at Siemens Mobility GmbH
- Maintenance and further development of several existing projects in the "AI-powered transportation" sector, based on React, REST-like APIs (Spring, Python) and various design libraries
- Responsible in the project for build processes, JavaScript development, architecture, coordination and communication with the design team
- Agile software development (Scrum, Kanban)
- Technologies: React, TypeScript, Ant Design, Node.js, Yarn, Vite, i18n, Postgres, Keycloak, Jest, Cypress, Storybook
- Tools: IntelliJ, Git, GitLab CI, Docker, Confluence, Jira
Timur Y.
Last position:
Lead Frontend Developer | Fullstack Developer at Finanz Informatik
- Further development of an application for managing personnel changes.
- Development of frontend and backend.
- Implementation of the frontend with React and Material UI.
- Implementation of the backend with Java and Spring Boot.
- Use of React, Java, Spring, TypeScript, next.js, Material UI, Github Enterprise, Figma, Docker, Playwright, swagger, swagger UI, OpenAPI, npm, yarn, git.
Artur S.
Last position:
Senior Consultant at MHP - A Porsche Company
Mojtaba G.
Last position:
Full-Stack Software Developer at Energy Sector
- Led and coordinated consumption and price calculations for gas and electricity forecasts to ensure accurate and reliable pricing
- Implemented modern microservices and Web APIs based on .NET 7 in an Azure environment using Azure App Service, Azure Storage, and Azure Service Bus
- Built and managed infrastructure in Azure using Terraform, including resource deployment and automation of deployment processes
- Developed and maintained Azure DevOps pipelines to optimize build, test, and release workflows
- Optimized data management with SQL Server and ensured seamless integration across all services
- Developed the front end with Angular 16, TypeScript, CSS, HTML, and Kendo UI to deliver an intuitive and engaging user interface
Igor P.
Last position:
Senior Frontend Developer at Objego GmbH
Within the project, Objego's digital platform for real estate management was further developed.
Further development of various software modules within the application.
Continuous improvement and optimization of existing functionalities to enhance performance and user experience.
Design and implementation of unit tests to ensure code quality and stability.
Close collaboration with the QA team to quickly fix bugs.
Implementation of new features in coordination with stakeholders and end users.
Active member of the Scrum team with a focus on agile methods and continuous improvement of the software.
Technologies: Angular 16/17, Material, Angular CDK, Angular Elements, Nx, NgRx, NgNeat, NgX-Translate, NgX-Charts, NgX-Lottie, NgX-Markdown, Sentry, Azure AI Form Recognizer, Lodash, Dayjs, Flatpickr, Lottie-Web, Mixpanel, RxJS, Prettier, ESLint, Webpack, Cypress, Playwright, Jest, Husky, TypeScript, Node.js, Zone.js, Docker, Spring Boot, Git, Figma, Figma Token, Storybook, Jira, Confluence, Atlassian, Gitlab CI/CD, Codecov, Custom Design System, Mockoon.
Discover over 15,000 top freelancers
Statistics of experts using Jest
Aggregated from the professional profiles of matched freelancers.
Experience
15 years (Germany: 16 years)
Position duration
1.8 years (Germany: 1.7 years)
Positions per freelancer
13 (Germany: 12)
Top business areas
Information Technology, Product Development, Project Management
Top industries
Information Technology, Banking and Finance, Healthcare
Certification focus areas
Information Technology, Product Development, Project Management
Bachelor's degree or higher
83% (Germany: 91%)
Master's degree or higher
17% (Germany: 44%)
Certifications per freelancer
3 (Germany: 1)
Most common languages
German, English, Russian
Speak two or more languages
100% (Germany: 97%)
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 Frankfurt 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 Frankfurt using Jest
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.
Jest 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 (89%)
- Healthcare (56%)
- Media and Entertainment (44%)
- Education (33%)
- Transportation (33%)
- Manufacturing (33%)
- Pharmaceutical (33%)
Please note that freelancers can work across multiple industries, so percentages overlap.
About the technology
Testing foundation
Jest is a JavaScript testing framework maintained by Meta and widely used for unit, integration, and snapshot testing. It supports JavaScript and TypeScript projects, runs tests in isolation, and provides built-in assertions, mocking, code coverage, and watch mode. Teams use it to protect web applications, Node.js services, libraries, and shared components from regressions.
Ecosystem and tooling
Jest fits naturally into React, Next.js, Node.js, Babel, and TypeScript projects. Strong professionals work with Jest configuration, test environments, module resolution, fake timers, setup files, and custom reporters. They also connect tests with npm scripts, GitHub Actions, GitLab CI, Docker-based pipelines, and coverage tools such as Istanbul.
- Configure Jest for JavaScript or TypeScript repositories
- Test React components, APIs, services, and utility modules
- Use mocks, spies, fixtures, snapshots, and test doubles
- Add coverage checks and stable CI execution
Where it fits
Companies bring in Jest expertise when a codebase has fragile tests, slow feedback, or limited regression protection. Specialists can establish a test strategy for a new product, modernize legacy suites, or add coverage around critical payment, commerce, healthcare, and SaaS workflows. In Frankfurt, remote collaboration is common, while some teams prefer on-site workshops for complex releases.
Project deliverables
Typical work includes a Jest configuration, reusable test utilities, component and service tests, snapshot policies, mocked external dependencies, and CI reports. Professionals may also document testing conventions, migrate suites from another framework, or integrate Jest into monorepos managed with Nx, Turborepo, or workspace tooling. The result should be readable, deterministic, and useful to the wider delivery team.
When to seek expertise
- Tests pass locally but fail intermittently in CI
- A React or Node.js release lacks regression coverage
- Mocking, async behavior, or module imports are hard to control
- A legacy suite needs faster execution and clearer structure
- Coverage reports exist but do not guide risk decisions
A freelance specialist is useful when the team needs focused testing knowledge without changing its long-term product structure. German or English communication can support collaboration with Frankfurt-based teams, depending on the organization and project setup.
Quality signals
Strong Jest professionals write tests that describe behavior rather than implementation details. They isolate external systems thoughtfully, handle asynchronous code without arbitrary delays, and avoid snapshots that hide meaningful changes. They can explain trade-offs between unit, integration, end-to-end, and contract testing, review flaky failures, and leave a suite that other contributors can extend with confidence.
Frequently asked questions
Key details about Jest, drawn from the questions we get asked most.
Jest is used to test JavaScript and TypeScript code, including React components, Node.js services, APIs, utilities, and shared libraries. It combines a test runner with assertions, mocking, snapshot testing, watch mode, and coverage reporting.
Jest offers an integrated testing experience with strong mocking and snapshot support. Vitest can provide fast execution in Vite-based projects, Mocha is more modular and often needs additional libraries, while Cypress focuses mainly on browser-based end-to-end and component testing rather than general unit testing.
A strong Jest specialist usually understands JavaScript or TypeScript, React or Node.js, asynchronous programming, HTTP APIs, and Git workflows. Experience with Babel, ts-jest, package managers, monorepos, and CI systems is also useful for production projects.
The required depth depends on the codebase and risk. A focused test addition may need a specialist who understands the application structure and existing conventions, while a migration, flaky-suite investigation, or CI redesign calls for deeper experience with Jest internals, test architecture, and build tooling.
Yes. Jest work is well suited to remote collaboration through repositories, pull requests, CI results, and shared test plans. Frankfurt teams can work with remote specialists or combine remote delivery with on-site discovery sessions, with German or English communication agreed at the start.
Review whether the tests are deterministic, readable, and focused on observable behavior. A capable Jest professional explains coverage gaps, keeps mocks realistic, handles async code correctly, and demonstrates that the suite gives useful feedback without excessive maintenance.
Jest can test both React applications and Node.js backends, but each environment may need different configuration. A specialist should select suitable test environments, isolate browser-specific behavior, mock network boundaries carefully, and keep frontend and backend tests aligned with their actual responsibilities.
Common problems include flaky async tests, overused snapshots, shared state between tests, inaccurate mocks, slow setup, and configuration conflicts in TypeScript or monorepos. Experienced Jest professionals trace failures to their source, simplify test boundaries, and improve feedback speed without weakening meaningful checks.
The average hourly rate of freelancers in Frankfurt, Germany who have used Jest in their recent projects is 88 €, which corresponds to a daily rate of about 701 € based on an 8-hour working day.
Of the freelancers in Frankfurt, Germany who have used Jest in their recent projects, 83% hold at least a Bachelor's degree and 17% hold at least a Master's degree.
On average, freelancers in Frankfurt, Germany who have used Jest in their recent projects have 15 years of professional experience, with a single engagement typically lasting around 1.8 years.
The most common languages among freelancers in Frankfurt, Germany who have used Jest in their recent projects are German (100%), English (100%), and Russian (22%).
The most common industries among freelancers in Frankfurt, Germany who have used Jest in their recent projects are Information Technology (100%), Banking and Finance (89%), and Healthcare (56%).
The most common business areas among freelancers in Frankfurt, Germany who have used Jest in their recent projects are Information Technology (100%), Product Development (100%), and Project Management (44%).
Main locations of FRATCH Experts, who have recently used Jest
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 Request a free demo
Get in touch with the FRATCH team and we will get back to you within 4 hours.
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We always have the time for a call or email!
Philipp Thomaschewski
FRATCH CEO
