Jest Experts in Berlin
for reliable JavaScript testing, matched in minutes with vetted freelance talentHire experts who build maintainable Jest test suites, configure React and Node.js testing workflows, and integrate coverage checks into CI pipelines. FRATCH matches you quickly and precisely with vetted, available freelancers who fit your technical needs.
Meet FRATCH Experts in Berlin, who have recently used Jest
Alois R.
Last position:
Senior Fullstack Developer at brandung GmbH
- Opt-in RAG extension over tenant-owned data sources (SharePoint, Confluence) on existing multi-tenant enterprise AI platform
- Architecture: ADRs, solution evaluations, permission strategy, cost modeling
- End-to-end SharePoint and Confluence connectors: OAuth consent flows, token refresh, metadata sync, search integration
- Permission resolution: ACL indexing at ingestion and query-time verification (document-level security)
- Elasticsearch hybrid search (semantic + keyword) with RRF scoring
- RAG chat with context injection and source citations
- Stack: Elastic Cloud, Elasticsearch, Docker, Northflank, Next.js, React, TypeScript, Prisma, Microsoft Graph API, Atlassian REST API, OAuth 2.0
Oleg A.
Last position:
Staff Software Engineer at Kpler Germany GmbH
- Delivered a new notifications platform implementation built from scratch to replace existing and upcoming services
- Collaborating with other teams to integrate more domains
Tech stack:
- Data: Scala 3, Apache Kafka, Python, Airflow, Astronomer
- BE-FE: TypeScript, NestJS, Java, Spring Boot, Vue
- Dev-ops: AWS, PostgreSQL, Docker, GitHub Actions, Kubernetes, Helm, ArgoCD
Alexandr K.
Last position:
Technical Co-Founder at Dealyv
- Joined the initial development team and helped transform an n8n prototype into a production-ready 0-to-1 product in a fast-paced environment.
- Owned delivery across CRM and Twilio integrations, customer communication workflows, and administrative interfaces.
- Collaborated on AI evaluation, microservice architecture, and other cross-functional product and engineering topics.
- Supported the CEO across VC communications, customer acquisition, product positioning, onboarding, documentation, pricing, and sales.
Anna M.
Last position:
Freelance Frontend Consultant at Mister Spex
- Developed complex React/TypeScript frontend systems for highly customizable lens products.
- Designed internal tooling for validating and managing product configuration constraints.
- Led accessibility initiatives to align customer-facing applications with EU accessibility requirements.
- Worked extensively in large legacy codebases while incrementally improving maintainability and developer experience.
- Collaborated across multiple teams in an international e-commerce environment.
Nada S.
Last position:
Freelance Senior Frontend Engineer at Self-Employed
- Senior software engineer focused on React, TypeScript and AI-assisted product workflows
- Build frontend systems for complex SaaS products, internal tools and operational workflows
- Recent work includes AI evaluation tooling, support reliability analysis and developer-focused QA systems
- Available for freelance and contract engagements, especially remote-first projects
Aruldass A.
Last position:
Web Module Lead at Mphasis Limited
- Led the end-to-end delivery of enterprise full-stack web applications by driving requirement analysis, solution design, frontend and backend development, database design, API integration, code reviews, team coordination, Agile execution, CI/CD deployments, production support, performance optimization, security implementation, and stakeholder collaboration to deliver scalable, high-quality software solutions.
Stefan D.
Last position:
Frontend Developer – Sports Event and City Portal Projects at München Betriebs GmbH
- Developed an accessible, responsive website based on Figma designs for a major sports event in compliance with WCAG, BITV and EN 301 549
- Planned and set up the tool stack with Vite, Playwright, Docker and GitLab CI
- Worked on two existing projects (Vue.js & Nuxt), focusing on bug fixing, accessibility audits and developing new features
- Collaborated with Design and QA to consistently implement accessible UI patterns
- Advised on improving existing frontend architectures in terms of accessibility, performance and maintainability
Maciej R.
Last position:
Full Stack Developer (Freelancer) at Runbuggy
- Led development of RunBot AI assistant autonomously using LLM-powered workflow automation (React, TypeScript, Java, MongoDB, NATS)
- Architected TMS platform providing unified transportation management and real-time logistics visibility with AI processing pipelines
- Designed event-driven microservices architecture supporting marketplace
- Drove architectural decisions and technical leadership across full-stack platform development
Alessandro L.
Last position:
Vue Frontend Engineer at Savills
- Savills is one of the world's leading property advisors with 700+ offices worldwide. In Berlin, I built core digital solutions for the valuation business, replacing legacy Access-based workflows with an enterprise-grade web app built on Vue.js.
- Frontend Architecture & Scalability: Designed scalable Vue + TypeScript frontend architecture for internal enterprise applications, integrating a Symfony backend and interactive maps.
- Legacy Modernization: Led the modernization of legacy jQuery-based systems into maintainable Vue-driven applications, improving performance, maintainability, and efficiency across business workflows.
- PDF Report Workflow Automation: Engineered Twig-based automated PDF generation pipelines that reduced manual report preparation time by ~80%, saving approximately 12h per analyst/month.
- Design System & Frontend: Built a scalable SASS-based design system using mixins, maps, functions, and reusable UI patterns for consistency and long-term maintainability.
Florian F.
Last position:
Fullstack Developer - freelance at cenfood GmbH
- Implementation of new features in backend and frontend in collaboration with the product team.
- Stack: Typescript, Vue 3, Node/Koa, TypeORM, GraphQL/Apollo, PostgreSQL, Github Actions, Weclapp
Mario J.
Last position:
Architect / Developer at handyhase
- Overhaul of the entire design and implementation of new UI/UX aspects using React
- Planning of the software architecture and structuring of the project for long-term scalability using Git for version control
Qaiser A.
Last position:
Freelance Lead DevOps Engineer at Schwarz Gruppe Produktion
Bootstrapping a CloudOps team and building a multi-cloud provider backend for a low-code Internal Developer Platform (IDP) with env zero
Introducing user story mapping, ADRs, milestones, and backlog management
Designing and developing core APIs, setting up CI/CD pipelines, OpenTofu/Terraform scripts
Representing and communicating the team with third-party stakeholders (e.g. env zero)
(Cross-)team coaching on DevOps, software design, Terraform, Golang, and agile practices
Julien L.
Last position:
MLOps Engineer at SAMGEN
- Building and scaling cloud infrastructure on GCP to support a SaaS platform for industrial clients
- Designing and implementing a data-driven DevOps pipeline for streamlined deployment and CI/CD workflows
- Collaborating with Data Science team on MLOps workflow to automate integrated retraining
Max D.
Last position:
Tech Lead, Interim CTO/CPO at MatchDispatch
I worked on automating cold outreach.
- Developed a queue architecture to support the parallel execution of large volumes of background tasks.
- Integrated multiple email delivery providers.
- Implemented an LLM-based data enrichment process.
Technologies: TypeScript, React, Node.js, Next.js, Drizzle ORM, PostgreSQL, Next-Auth, JWT, Docker, Kubernetes, AWS, CloudFlare, Traefik, Groq, Jest, Figma
Adam H.
Last position:
AI Software Engineer at Adevinta
- React
- Python
- Langchain
- GPT
- Typescript
- AWS
- Bedrock
- Docker
- Developing AI powered marketplace tools for a range of solutions across the Adevinta ecosystem.
Discover over 15,000 top freelancers
Statistics of experts using Jest
Aggregated from the professional profiles of matched freelancers.
Experience
16 years
Position duration
1.5 years (Germany: 1.7 years)
Positions per freelancer
13 (Germany: 12)
Top business areas
Information Technology, Product Development, Quality Assurance
Top industries
Information Technology, Media and Entertainment, Retail
Certification focus areas
Information Technology, Product Development, Business Intelligence
Bachelor's degree or higher
95% (Germany: 92%)
Master's degree or higher
50% (Germany: 45%)
Certifications per freelancer
1
Most common languages
English, German, Spanish
Speak two or more languages
96% (Germany: 97%)
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 Berlin 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 Berlin 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 29 Oct 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%)
- Media and Entertainment (61%)
- Retail (61%)
- Banking and Finance (57%)
- Education (52%)
- Healthcare (35%)
- Manufacturing (35%)
- Government and Administration (35%)
Please note that freelancers can work across multiple industries, so percentages overlap.
About the technology
What Jest does
Jest is a JavaScript and TypeScript testing framework for checking application behavior with fast, isolated test runs. It supports unit, integration and snapshot testing, making it a common choice for React interfaces, Node.js services and shared libraries. Facebook's Jest project is now maintained as an open-source tool within the JavaScript ecosystem.
Core capabilities
Jest combines a test runner, assertion library, mocking system and coverage support in one workflow. Its watch mode helps specialists receive rapid feedback while changing code, and its parallel execution can shorten feedback cycles for larger suites. Configuration can be shared across packages or adapted to a specific repository.
- Write unit and integration tests for JavaScript and TypeScript
- Mock modules, timers, network calls and browser APIs
- Validate React output with snapshots and Testing Library
- Track coverage and enforce quality checks in CI
Ecosystem and tooling
Strong Jest work often includes React Testing Library, Node.js, TypeScript, Babel or ts-jest, and package managers such as npm, Yarn or pnpm. Professionals also connect Jest with GitHub Actions, GitLab CI or other build systems. In Berlin teams, this combination is useful for web products, digital services and API-backed applications that need dependable release checks.
When to bring in expertise
Companies usually seek freelance expertise when a codebase has little test coverage, flaky tests or slow feedback in continuous integration. Specialists can establish a test strategy, migrate suites from another runner, or protect a critical feature before a release. They can also review existing tests and separate useful behavioral checks from brittle implementation details.
- A React or Node.js codebase changes faster than its tests
- CI failures are difficult to reproduce locally
- A migration from Mocha, Jasmine or another runner is underway
- Coverage exists but does not reflect user-critical behavior
What strong professionals deliver
A capable Jest specialist chooses test boundaries that reflect how the system is used. They keep mocks purposeful, use realistic fixtures, isolate external services and explain why a test should fail. They also understand asynchronous code, promises, fake timers, module resolution, DOM environments and TypeScript configuration.
Working together effectively
A project starts more smoothly when the repository, existing scripts and quality goals are available from the outset. Remote collaboration works well when test failures, coverage changes and review decisions are visible in pull requests and CI logs. On-site work in Berlin can help when testing touches product discovery, shared release planning or close collaboration with a local team.
Frequently asked questions
Everything clients usually want to know about Jest, in one place.
Jest is used to test JavaScript and TypeScript code, including React components, Node.js services and reusable packages. It can run unit, integration and snapshot tests while providing assertions, mocks, coverage reports and watch mode.
Compared with Jest, Mocha and Jasmine usually require more separate choices for assertions, mocking and coverage. Jest offers an integrated setup, while Mocha can provide more flexibility for teams that want to assemble their own testing stack.
A strong Jest freelancer should understand JavaScript or TypeScript, asynchronous programming and the application framework under test. React Testing Library, Node.js, API testing, Git workflows and continuous integration are also valuable adjacent skills.
The right level depends on the test architecture, not only the size of the codebase. A specialist who can inspect existing patterns, identify risky behavior and create a maintainable first suite is often more useful than someone who only writes isolated test cases.
Yes. Jest work is well suited to remote collaboration because test files, CI results and coverage changes are visible in the repository. Teams in Berlin should agree on communication routines, review practices and any German or English language expectations before work begins.
Jest pairs well with React Testing Library when a team wants to verify components through user-facing behavior rather than private implementation details. The combination supports readable tests for rendering, interaction, forms and asynchronous UI states.
Review whether the tests cover important behavior, fail for meaningful reasons and remain stable when implementation details change. High-quality Jest work also keeps setup understandable, limits unnecessary mocks and makes failures easy to diagnose in local runs and CI.
A Jest specialist should clarify the repository structure, runtime, package manager, current test command and CI environment. They should also ask which risks matter most, whether existing tests are trusted and how the team defines acceptable coverage and release confidence.
The average hourly rate of freelancers in Berlin, Germany who have used Jest in their recent projects is 84 €, which corresponds to a daily rate of about 674 € based on an 8-hour working day.
Of the freelancers in Berlin, Germany who have used Jest in their recent projects, 95% hold at least a Bachelor's degree and 50% hold at least a Master's degree.
On average, freelancers in Berlin, Germany who have used Jest in their recent projects have 16 years of professional experience, with a single engagement typically lasting around 1.5 years.
The most common languages among freelancers in Berlin, Germany who have used Jest in their recent projects are English (100%), German (91%), and Spanish (13%).
The most common industries among freelancers in Berlin, Germany who have used Jest in their recent projects are Information Technology (100%), Media and Entertainment (61%), and Retail (61%).
The most common business areas among freelancers in Berlin, Germany who have used Jest in their recent projects are Information Technology (100%), Product Development (100%), and Quality Assurance (57%).
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.
Hamburg 
Munich 
Frankfurt Request a free demo
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Philipp Thomaschewski
FRATCH CEO
