
Swagger Expert
for clear API contracts, testing and integration, matched in minutes with vetted professionalsHire experts who define OpenAPI specifications, generate interactive API documentation and connect Swagger tooling with automated tests and CI pipelines. FRATCH matches you quickly and precisely with vetted, available freelancers who fit your project.
Meet FRATCH Experts who have recently used Swagger
Lutz E.
Last position:
Freelance Software Developer – GoPro MultiCam Control via COHN at Plutos Company UG
- Developed a pilot system to control and monitor multiple GoPro cameras
- Implemented start, stop, status, media, download and diagnostic functions via COHN endpoints
- Built camera detection, individual and group control, and stable session/KeepAlive logic
- Set up a download pipeline with a queue, retry handling and temporary files
- Ensured consistent session, folder and file naming for multicamera recordings
- Integrated provisioning, certificates and network operations
Jörg T.
Last position:
Consultant, Requirements Engineer and Database Expert
Project – Evaluation and development of databases for a new product line for a measuring equipment manufacturer
- Current-state analysis
- Requirements analysis of the data storage layer
- Writing benchmark tests
- Design of the new database schema
- Database migrations
- Development of audit logging and Part11
- Creation of backup and recovery concepts
- Design of the persistence layer API
- Writing unit tests
- Creating requirements in Azure
Tools: C#, Visual Studio 2022, Azure DevOps, SonarQube, Git, RestSharp, WebServer, PostgreSQL, MS SQL, SQLite, MinIO, Podman, Docker, DataGrip, SQL Management Studio, HeidiDB, pgAdmin
Reinhold M.
Last position:
Business Requirements Engineer, Proxy Product Owner, Tester at AXA Konzern AG
Working Environment
- Insurance / Claims Management (Property, Liability, Automotive)
- REST-based ClaimAPI with Guidewire ClaimCenter
Scope
- Further development of the internal REST-based ClaimAPI with Guidewire ClaimCenter as the backend and various portals/front-end offices as clients, and with the following objectives: + increased AI-supported claims processing outside of Guidewire ClaimCenter + and support for all lines (property, liability, automotive).
- Further development of automated claims processing
Activities
- Interfacing IT & Business
- Design activities with documentation in Confluence, Jira: + Requirements engineering (functional and non-functional) + Design of REST endpoints and coordination with interface partners (esp. AI-colleagues) + Identification, design and evaluation of alternative solutions (moving away from a monolithic approach toward fine-grained endpoints, with code reuse across all lines if possible) + Creation / refinement of product backlog items in Jira, i.e. epics, user stories and tasks, incl. alignment with developers & POs during (pre-)refinement sessions + Using AXA Secure GPT when creating / refining user stories (description, acceptance criteria) and designing REST endpoints + Estimation and prioritization of user stories and tasks during Sprint Planning sessions + Coordination and support during the implementation of Product Backlog items + Driving decision making with preparation and presentation of decision-making documents
- Quality assurance: + Test management, including test case creation using Xray in Jira + Test execution using Bruno as REST client and in Guidewire ClaimCenter + Submission of test artifacts for PO approval + Analysis of production bugs
Methods Big Room Planning (aka PI-Planning in SAFe), Scrum, BPMN, EPK, UML, ERM, DDD
Tools / Tech Stack Teams, Confluence, Jira with Xray, OpenAPI/Swagger, REST, JSON, XML, MS Office, Bruno, GitHub repository (reading), Guidewire ClaimCenter, AXA Secure GPT (AXA's in-house GenAI solution based on Azure OpenAI)
Onur K.
Last position:
Project Manager & Outsourcing Manager at SENEC GmbH (EnBW Group)
- Built a scalable nearshore IT developer hub (Croatia, Czech Republic, Poland) as an independent company through a BOT model (Build – Operate – Transfer)
- Identified, selected, and managed full-service agencies; introduced management and control mechanisms, including KPIs, SLAs, and regular service reviews
- Prepared and reviewed data processing agreements and framework contracts in coordination with Legal & Compliance; integrated regulatory requirements (including KRITIS) into process design
- Advised on cloud vs. on-premise strategies, data storage, and authorization concepts; supported Procurement with tendering and service provider evaluations
- Managed change and process harmonization between internal teams and nearshore partners; reported to executive management, CFO, and CIO
Result: Scalable IT developer hub with an audit-ready governance model, reduced operating costs, and accelerated product development.
Ornel Franck W.
Last position:
Sales Partner at ERGO PRO
- Industry: Insurance, Trade, IT
- Customers & Projects: Consulting and selling insurance and similar services
- Main tasks: Insurance consulting (health insurance, retirement planning, wealth building); commercial services, inside and field sales; sales data analysis and forecasting; customer consulting and support; opening a new sales headquarters for private and business customers; business development & innovation management; business use case development; process optimization; stakeholder management; team leadership and training; preparation and delivery of trainings;
- Technologies used: Microsoft Office 365, Microsoft Teams, Jira, Draw.IO, Camunda 8, Java (8, 17,21,25), Git, Spring Boot, Spring Batch, Spring Data REST, Spring Web, Spring Security, J-Unit, Playwright, Lombock, Vaadin, H2, PostgreSQL (16, 17 18), pgAdmin, Docker, LLMs, JasperSoft Studio, JasperReports
Sercan T.
Last position:
Co-Founder & Lead Software Architect at Pflege-Pfad
- Focus: System architecture, cloud-native platforms, microservices, API design
- Product: Pflege-Pfad is a digital placement platform that directly connects relatives of people in need of care with verified care services and caregivers – without an agency and without ongoing fees.
- Business analysis & process design:
- Analysis of the German care market and identification of the key pain points of both target groups.
- Modeling of core business processes: registration, verification, care request, application, placement, and rating.
- Definition of the business model as a freemium/premium model with optional contact unlocking.
- Creation of user stories and requirements documentation for relatives, care services, and administrators.
- Design of trust and quality assurance mechanisms with document upload, admin review process, and rating system.
- Coordination with stakeholders and validation of product decisions with potential users.
- Technical implementation:
- Design and implementation of the entire platform architecture as the sole developer.
- Design and implementation of a REST API with Spring Boot and Kotlin, including JWT-based authentication.
- Development of the frontend as a single-page application with Angular 17.
- Implementation of the AWS infrastructure with EC2, RDS PostgreSQL, S3, CloudFront, and IAM.
- Document upload with AWS S3 using presigned URLs to verify care services.
- Email notifications via Resend API.
- AI-supported care service search via OpenAI API.
- Implementation of complete user flows such as registration, login, password reset, and the placement process.
- Development of an admin panel for user and care service management as well as analytics.
- CI/CD with GitHub Actions and containerized deployments with Docker.
- End-to-end tests with Playwright.
Technologies: Kotlin, Spring Boot 3, Spring Security, JWT, JPA/Hibernate, PostgreSQL, Angular 17, TypeScript, RxJS, AWS (EC2, ECS, S3, CloudFront CDN, RDS PostgreSQL, IAM), nginx, GitHub Actions, Playwright, Maven, Git, OpenAI API, Resend API, Docker, Scrum, i18n (DE/EN/TR), Kiro, feature flag architecture.
Toralf C.
Last position:
IT Consultant in PKI Software Development at BWI
- Implementation of a full-stack application with Angular as frontend framework and Java as backend language
- Use of the Swagger OpenAPI specification for REST communication between frontend and backend applications
- Control of a card printer via the Nexus Card SDK framework
- Design and implementation of card management software with web interface and JavaFX module for printer monitoring
- Use of Cucumber tests for test automation and creation of test artifacts for testing outside the development environment
- Use of Wireshark for network investigations to analyze the API of a third-party product and to check the REST API of the self-developed software
Emre S.
Last position:
IT Project Manager | SAP E-Invoicing Outbound at Rohde & Schwarz
Project: Introduction of statutory-compliant electronic invoicing (outbound, Germany) in SAP for an international technology group.
- Project management: Planning, steering and reporting of the E-Invoicing outbound rollout across all affected business areas, including budget and resource coordination.
- UAT: Structured user acceptance test with key users per business area, test cases per invoice scenario, and consolidated test results for decision making.
- Defect management: Handover and tracking of defects in Jira, including validation of the generated invoices against the statutory schemas.
- Cutover, go-live and hypercare: Readiness checks and cutover planning aligned with the statutory deadlines, coordination of go-live and stabilization during hypercare.
- Stakeholder management and reporting: Alignment with Finance, Tax, business departments and IT, preparation of status reports and decision papers, and consistent follow-up of open items.
- Change management and documentation: Communicated process changes to the business departments, enabled key users, and created process and compliance documentation to ensure traceability and audit readiness.
Ales L.
Last position:
Senior DevOps Consultant (Freelance) at European Union Agency (via IBM)
- Worked as freelance Senior DevOps Consultant on-site for IBM at a European Union Agency, operating in a highly secure, air-gapped environment managing classified systems.
- Led automation and DevOps initiatives for a large-scale OpenShift platform (>400 nodes), driving deployment efficiency, GitOps adoption, and operational automation using Ansible, Python, and Bash while ensuring compliance with security requirements.
- Spearheaded automation of release and deployment workflows in a private cloud environment hosting 400+ OpenShift nodes, significantly improving deployment speed and reliability.
- Migrated existing playbooks, roles, and templates from Ansible Tower to Ansible Automation Platform (AAP), ensuring full compliance with fully-qualified collection names (FQCN) and preparing custom Execution Environments (EE) for containerized automation.
- Implemented GitOps Agent for AAP Controller Configuration as Code, enabling automated synchronization (CRUD) of Ansible Controller objects based on repository-stored configuration definitions using GitHub webhooks.
- Designed and automated complex multi-step operational workflows including environment cleanup, Helix cluster component re-creation, Kafka topic management, and OpenShift object lifecycle management across ~100 environments.
- Achieved a reduction of multi-day manual operations to under a few hours through automation improvements spanning multiple AAP clusters and OpenShift environments.
- Integrated Ansible Automation Platform with Thycotic (Delinea) Secret Server via lookup plugin to enhance secure credential management in automated processes.
- Managed deployment tasks, platform troubleshooting, and Istio network configurations while adhering to stringent EU PSC security and compliance standards.
- Collaborated with infrastructure and application teams to refine deployment procedures, develop naming conventions, and continuously improve automation coverage in an air-gapped, classified environment.
Will O.
Last position:
Solution Architect at Polizei Behörde Stuttgart
Designed a migration strategy for WLS applications to BKA Cloud and Stack IT
Created a hybrid cloud for internal testing and development with Kubernetes
Transformed the IT landscape from an outdated monolithic architecture to a cloud-based architecture
Integrated new CI/CD processes using Azure Pipelines
Quadrupled the processing throughput for personnel security checks
Migrated personnel security screening applications to Docker-based applications
Implemented CI/deployment pipelines using Azure DevOps
Environment: Java Springboot, Kubernetes, Oracle Weblogic, OpenID, Camunda, JUnit, TOGAF
Michael N.
Last position:
Senior AI Engineer | Forward Deployed Engineer at Tiefbau
- Development of an AI-powered project organization tool for a civil engineering company that intelligently links project, task, tender, schedule, and document data through a knowledge graph.
- Implementation of AI features for document analysis, information extraction, context-based assistance, and voice-based data capture based on Microsoft Azure AI, reducing administrative effort, making information available faster, and supporting project teams in decision-making.
- Tech stack: Python, React, TypeScript, FastAPI, Claude Code, Codex, Graphify, PostgreSQL, Microsoft Azure AI Foundry, Azure OpenAI, Azure AI Speech, Azure AI Document Intelligence, Microsoft Graph, Microsoft Entra ID, Docker, Git, CI/CD.
Sumalatha B.
Last position:
BC_CDR: Cloud Detection & Response | AI / Cybersecurity at Banyan Cloud
Real-time AWS threat detection using LLMs, UEBA, and vector analytics
- Built UEBA engine processing millions of CloudTrail/GuardDuty events to detect behavioural anomalies in real time.
- Integrated Amazon Bedrock LLMs for narrative threat analysis and structured automated incident summarisation.
- Designed vector embedding pipeline (MongoDB Atlas) for entity behaviour comparison and semantic anomaly detection.
Tech: Python, FastAPI, AWS, MongoDB Atlas, Amazon Bedrock, Pydantic, Motor (Async).
Ramazan C.
Last position:
Fullstack-/DevOps Engineer at BKA (Federal Criminal Police Office)
Development and further development of an internal platform for managing and providing technical resources, virtual machines, and infrastructure services. The platform supports self-service processes and covers functions that are conceptually comparable to cloud management solutions like Azure or AWS.
- Responsible involvement in the design, development, and implementation of new backend and frontend features
- Hands-on development with Java, Spring Boot, Python, and Angular
- Implementation of REST interfaces, business logic, validations, and integrations into existing system landscapes
- Further development of modern web interfaces with Angular, including connection to backend services
- Participation in architecture and design decisions within the team, especially with regard to scalability, maintainability, and clean interfaces
- Containerization and deployment of applications with Docker, Kubernetes, and Helm
- Support with CI/CD processes and deployment to Kubernetes-based environments
- Work in the environment of vSphere, Broadcom, GitLab CI/CD, ArgoCD, Maven, npm, and NuGet
- Close collaboration with developers, business teams, DevOps, and other technical stakeholders
- Analysis of technical requirements, deriving suitable solutions, and independent implementation in an agile team
- Use of GitHub Copilot to support code generation, refactoring, test case creation, and technical documentation
Methods/ tools/ technologies: Languages & frameworks: Java (21), Spring Boot (4.x), Python, Angular, Robot Framework, Kubernetes, Helm Persistence: PostgreSQL, MongoDB, Hibernate, Liquibase Architecture & communication: REST, gRPC, GraphQL, Apache Kafka, OpenAPI, Microservices, Event Driven, Domain Driven Design Cloud & infrastructure: Terraform, Docker, Rancher, Helm, Ansible Security: OAuth2, MS (Entra ID), web security, Keycloak (extensions for detailed group rights) DevOps: GitLab CI/CD, Ansible, Maven, Gradle, Grafana, Prometheus, Git, GitHub Copilot Testing & QM: JUnit, Robot Framework, automated component and integration tests, E2E tests with Playwright, Testcontainers, EasyMock Methodology & approach: Kanban, JIRA, Confluence, Clean Code
Aleksei R.
Last position:
QA Engineer at Cybus GmbH
- Led QA and test automation for a distributed industrial IoT and data-integration platform connecting shop-floor systems with enterprise applications.
- Designed and maintained automated API and UI tests using Playwright, TypeScript, and Python, covering REST APIs, authentication, resource management, integrations, permissions, and end-to-end workflows.
- Tested distributed services, data pipelines, messaging infrastructure, containerized applications, and integrations across Kubernetes, OpenShift, Docker, and Docker Compose environments.
- Performed functional, integration, regression, endurance, resilience, load, chaos, and exploratory testing across complex distributed systems.
- Used Chaos Mesh and Toxiproxy for network fault injection, latency, packet loss, and partition scenarios to validate system resilience and failure handling.
- Automated infrastructure provisioning, configuration, and environment setup with Ansible and managed deployments using Kubernetes and Helm.
- Tested integrations with industrial protocols, messaging systems, databases, HTTP/REST APIs, and external enterprise systems using simulators, emulators, and dedicated test environments.
- Worked with MQTT, Kafka, SQL databases, InfluxDB, REST APIs, OAuth 2.0, JWT, LDAP, Active Directory, OpenLDAP, mTLS, TLS, MFA, SSO, and RBAC.
- Investigated and resolved 40+ defects across backend services, integrations, distributed components, and web applications, using AI-assisted analysis with Claude to accelerate debugging, test design, and root-cause investigation.
- Improved deployment reliability through Kubernetes/OpenShift configuration and health-check tuning and monitored distributed systems using Grafana, Prometheus, and Loki.
- Collaborated with developers and product teams on sprint planning, technical refinement, quality strategy, release testing, and continuous improvement.
- Applied AI-assisted and agentic testing approaches to expand automated coverage and identify complex edge cases.
Matthias S.
Last position:
Software Developer and Consultant at CLADE GmbH
- Analysis of the existing CAN communication between microcontrollers
- Analysis of the sensors used and the measured values collected
- Planning the CAN messages for transmitting the measured values
- Iterative adjustment of the microcontroller code to the new CAN messages
- Cross-compilation from x64 to arm64
Discover over 15,000 top freelancers
Statistics of experts using Swagger
Aggregated from the professional profiles of matched freelancers.
Experience
19 years

Position duration
1.7 years

Positions per freelancer
14

Top business areas
Information Technology, Product Development, Quality Assurance

Top industries
Information Technology, Banking and Finance, Automotive

Certification focus areas
Information Technology, Product Development, Project Management
Bachelor's degree or higher
90%
Master's degree or higher
55%
Doctorate
9%

Certifications per freelancer
2

Most common languages
English, German, French

Speak two or more languages
98%
Based on our profile pool as of 5 Nov 2026.
Daily rate distribution
The chart shows how the daily rates of experts in this technology 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 using Swagger
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 5 Nov 2026. Actual rates may vary depending on seniority level, experience, skill specialization, project complexity, and engagement length.
Swagger 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 (96%)
- Banking and Finance (59%)
- Automotive (46%)
- Retail (42%)
- Manufacturing (40%)
- Government and Administration (39%)
- Healthcare (35%)
- Insurance (34%)
Please note that freelancers can work across multiple industries, so percentages overlap.
About the technology
What Swagger does
Swagger is a set of tools for describing, documenting and testing HTTP APIs. Its specifications are now maintained under the OpenAPI name, while Swagger remains widely used for the editor, UI and code generation tools. A clear API contract helps frontend teams, external partners and backend services work against the same interface.
Core deliverables
Swagger specialists turn API behavior into usable, reviewable documentation and contracts. They define endpoints, parameters, authentication flows, request bodies, response schemas and error formats. Typical deliverables include:
- OpenAPI specifications in YAML or JSON
- Interactive Swagger UI documentation
- Mock servers and example responses
- Client or server code generated from the contract
- API validation and regression tests
Ecosystem and tooling
The ecosystem includes Swagger Editor, Swagger UI and Swagger Codegen, alongside the OpenAPI Specification. Professionals often connect these tools with Postman, REST Assured, contract-testing frameworks and API gateways. They may also work with JSON Schema, OAuth 2.0, JWT, webhooks and CI systems that validate specification changes before release.
When companies need help
Freelance expertise is useful when an API is being designed, modernized or exposed to customers and partners. It also matters when documentation has drifted from production behavior or several teams need a shared contract. Common signals include:
- Consumers cannot discover endpoints or expected payloads
- Breaking changes reach clients without warning
- API documentation is maintained manually and inconsistently
- Teams need mocks before backend services are complete
Skills that matter
Strong professionals understand HTTP semantics, REST design, versioning and backward compatibility, not just the Swagger interface. They can read application code, inspect live traffic and choose accurate schemas for nested data, pagination and errors. Experience with authentication, automated validation and API lifecycle governance helps turn documentation into a reliable engineering asset.
Choosing the right specialist
Ask for examples of specifications that stayed aligned with live APIs and supported real consumers. A capable specialist explains trade-offs between contract-first and code-first workflows, handles reusable components cleanly and makes security schemes understandable. They should also be able to review an existing OpenAPI file, identify gaps and leave maintainable processes that the internal team can continue using.
Frequently asked questions
Everything clients usually want to know about Swagger, in one place.
Swagger is used to describe, document and test HTTP APIs through an OpenAPI specification and related tools. Teams use Swagger UI to publish interactive reference material and Swagger Editor to create or review API contracts.
Swagger describes the intended API contract, while Postman is primarily used to send requests, organize collections and run workflow-based tests. They work well together: a specification can guide test creation, while Postman can verify behavior against documented endpoints.
Swagger work benefits from knowledge of HTTP, REST conventions, JSON Schema, authentication and API versioning. Useful adjacent skills include CI pipelines, contract testing, API gateways, OAuth 2.0 and the backend framework that serves the API.
A Swagger assignment may be straightforward when the API is small and stable, but larger contracts require careful decisions about reuse, compatibility and security. Choose a specialist who has handled the API lifecycle involved, including design, review, validation and documentation updates.
Swagger work is well suited to remote collaboration because specifications, pull requests and generated documentation can be reviewed online. Clear ownership of the contract, access to API environments and regular communication are more important than physical presence.
High-quality Swagger documentation matches real responses, explains authentication and error cases, and gives consumers useful examples. Review whether schemas are reusable, operation names are clear and automated checks prevent the specification from drifting away from production.
Swagger remains relevant because its tools are widely used with the OpenAPI Specification, which is the current name for the standard. The important distinction is between the specification itself and tools such as Swagger UI, Swagger Editor and Swagger Codegen.
Before starting a Swagger assignment, clarify whether the team follows a contract-first or code-first process, which OpenAPI version is required and who owns approvals. Also confirm the source of truth, target consumers, authentication model and how validation will run in the delivery pipeline.
The average hourly rate of freelancers who have used Swagger in their recent projects is 94 €, which corresponds to a daily rate of about 756 € based on an 8-hour working day.
Of the freelancers who have used Swagger in their recent projects, 90% hold at least a Bachelor's degree, 55% hold at least a Master's degree, and 9% hold a doctorate.
On average, freelancers who have used Swagger in their recent projects have 19 years of professional experience, with a single engagement typically lasting around 1.7 years.
The most common languages among freelancers who have used Swagger in their recent projects are English (98%), German (96%), and French (17%).
The most common industries among freelancers who have used Swagger in their recent projects are Information Technology (96%), Banking and Finance (59%), and Automotive (46%).
The most common business areas among freelancers who have used Swagger in their recent projects are Information Technology (99%), Product Development (94%), and Quality Assurance (66%).
Main locations of FRATCH Experts, who have recently used Swagger
Our freelancers and interim experts are at home all over Germany — available on-site in Berlin, Hamburg, Munich and every major business hub, or fully remote. Choose a city to discover matched specialists, local market insights and up-to-date availability.
In Austria our freelancers and interim experts support companies from Vienna to Graz — on-site where your project needs them, or fully remote. Choose a city to discover matched specialists, local market insights and up-to-date availability.
Across Switzerland our specialists are active in Zurich, Geneva, Basel and Bern — working on-site or fully remote. Choose a city to discover matched specialists, local market insights and up-to-date availability.
Countries:
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