
JSON Experts in Frankfurt
matched in minutes with vetted and available freelance specialistsHire experts who design reliable data contracts, integrate REST and GraphQL APIs, and validate complex payloads across web, mobile and enterprise systems. FRATCH matches you quickly with precise, vetted and available freelancers for your JSON project.
Meet FRATCH Experts in Frankfurt, who have recently used JSON
Olga L.
Last position:
Business Analyst at VisualVest (Union Investment)
- Analyzed, structured, and documented business requirements for digital investment solutions, such as robo-advisors.
- Designed applications for new retirement products, including user flows, UX requirements, and functional specifications.
- Modeled and optimized business processes and coordinated with stakeholders while taking regulatory requirements in the financial sector into account.
Ali A.
Last position:
Founder & Architect at Independent AI R&D
- Fully on-premises LLM document-examination platform for a compliance-critical banking domain: agentic LangGraph pipeline with deterministic verification, every AI judgment structured and source-anchored; ~960 automated tests, zero data egress
- GPU throughput engineering (quantized serving, speculative decoding, prefix caching): 9.5x extraction speed-up, 500+ multi-document case files per day on a single A100
- AI-native EDI/EDIFACT integration platform (~116k LOC Java 25 / Spring Boot 4, 1,900+ tests): LLM-drafted partner mappings machine-verified before go-live (DFDL conformance, field-coverage checks, dry runs), ~99.5% byte match on real customer files — replacing weeks of manual mapping per partner
Prasad T.
Last position:
Solution Architect / Senior Manager – DTC E-Commerce Platform at BRITA
- Led discovery phase and POC for Shopware to Shopify Plus migration across EMEA markets, evaluating platform suitability, technical architecture, and multi-brand/multi-country capabilities against business requirements.
- Designed reference architecture for Shopify Plus implementation incorporating headless front-end patterns (Vue.js, Nuxt.js), CMS integration (Magnolia), and Azure middleware (APIM, Functions, Logic Apps, Service Bus) for 11 EMEA markets.
- Defined migration strategy analyzing data mapping, cutover approach, and zero-downtime deployment patterns using Varnish caching, GitOps pipelines, and CI/CD orchestration across six vendor teams.
- Architected multi-tenant Shopify Plus governance model with centralized admin, localized storefront customization, and compliance controls (GDPR, data residency).
- Prototyped AI-driven search optimization (LLM.txt, JSON-LD) for product discoverability in Google AI results, demonstrating post-launch performance opportunities.
- Defined EMEA expansion roadmap for 15+ markets through C-level strategic workshops, identifying phased rollout, market-specific configurations, and resource requirements.
- Tech Stack: React, Nuxt.js, Vue.js, Magnolia CMS, Shopware, Shopify Plus, Azure (APIM, Functions, Logic Apps, Service Bus, Front Door), Varnish, SAP, MS Dynamics, Docker, Kubernetes, GitHub Actions, PostgreSQL, Kafka
Torsten F.
Last position:
Data Analyst, Requirements Manager at Isabellenhütte Heusler GmbH
Analysis of the existing reporting platform, including processes and governance topics, with stakeholders from Sales and Marketing.
Detailed analysis and evaluation of customer-defined requirements for existing reporting and new dashboards to be established.
Support for stakeholders in managing sales processes and identifying KPI trends at an early stage.
Use of Microsoft Power BI as the central analysis and reporting platform.
Development of a proposal for the required further development of processes and the Power BI platform.
Documentation of AS-IS business processes and derivation of company-wide KPIs, including coordination with stakeholders.
Analysis and assessment of the customer's Power BI platform.
Analysis of processes and data governance.
Documentation of AS-IS business processes.
Development of recommendations for further developing processes and the reporting platform.
Design and implementation of dashboards in Power BI.
Development of company-wide KPIs and coordination with stakeholders.
Microsoft Power BI.
Data analytics.
KPI definition and reporting.
Dashboard design and data visualization.
Stakeholder management and requirements management.
Kevin F.
Last position:
DevOps and Platform Engineer at DB Systel GmbH
- Error analysis and fixes including performance optimization of the in-house developed platform API
- Change and incident management in day-to-day operations
- Responsible for compliance with security and compliance requirements
- Vendor management for software development and maintenance
- Planning and execution of migration of legacy services to a cloud native platform
Role in the project: project staff, implementation team
Used skills: requirements analysis, IT service and application management, IT operations, error analysis and performance optimization, software maintenance and lifecycle management
Project environment: Cloud Native Platform (Kubernetes, Crossplane, AWS, ArgoCD, Grafana)
Jörn B.
Last position:
Project Management and PMO at TANKKARTEN | PAYMENT
- Close collaboration with development teams to ensure alignment with project objectives
- Assessment of in-scope assets, creation of requirements, and support of the public tender process through the selection of a provider
- Creation and maintenance of UML sequence diagrams to document system interactions
- Extensive use of Agile/Scrum methodology and Spotify model
- Development and implementation of cutover and dress rehearsal plans together with the application managers
Basil S.
Last position:
Senior Developer / Data Engineer at Large energy-sector company
- Co-founded the Real-Time Data team, which grew to 10 members over time.
- Developed and delivered core data products.
- Optimized real-time application performance and implemented monitoring, alerting and logging solutions to ensure system stability.
- Created and maintained deployment pipelines.
- Collaborated with teammates, architects and experts in an agile Scrum environment.
- Operated applications, analyzed, tested and troubleshot software solutions.
Onik M.
Last position:
SAP SuccessFactors & S4HANA Consultant at Banking Industry
Extracted relevant infotypes from SAP HCM for migration to SuccessFactors Employee Central and mapping to ECP fields.
Configured P2P integration including BAPI setup and secured data exchange with HTTPS and OAuth protocols.
Set up foundational settings in Recruiting (REC) including roles, permissions, and job requisition templates.
Implemented Career Site Builder to create a branded candidate experience and integrated external job boards.
Configured candidate application workflows, screening, interviewing, and hiring communication templates.
Set up pre-screening questions and assessment tools including DHB sanction list checks.
Implemented automated background check and KYC integration with external vendors in the REC module.
Localized job requisition templates to reflect regional job titles and regulatory compliance.
Customized onboarding document templates and localized document archiving protocols (DRTM).
Adjusted onboarding forms to capture country-specific employee information including Form I-9.
Enabled Form I-9 remote document verification and integrated eVerify with SuccessFactors.
Set up automated reminders for employees and HR to complete I-9 sections within deadlines.
Configured pre-Day 1 access for new hires to complete tasks and mandatory trainings prior to start date.
Enabled e-signature integration for onboarding documents to support remote verification.
Technologies: SAP SuccessFactors, BTP, CPI, HCM onPremise, EC, ECP, REC, ONB, Form I-9, eVerify, S4HANA.
Ulm P.
Last position:
DataStage ETL Expert at ING Bank
- Datastage 11.7, dbt, Oracle 19, Python 3.12 / PySpark 3.5, Azure GitHub, Azure DevOps, Automic
- Development of migration jobs to transfer data from the collection DWH to the new Risk Mart, as well as development of ETL pipelines to migrate historical data from the old Mart to the new Risk Mart.
- Storage of the silver layer on Hadoop and the gold layer in Oracle.
- Translation of DataStage jobs into dbt to publish reporting data in Google Cloud to a PostgreSQL database.
- Creation and optimization of complex SQL queries for data extraction from a data vault, taking into account historical data in the point-in-time tables.
- Creation of Oracle table definitions (DDL) and adjustment of existing stored procedures.
- Versioning changes in GitHub and deployment via the CI/CD portal.
- Refactoring long-running DataStage jobs into Python using PySpark to reduce server load.
- Migration of SAS scripts to PL/SQL, including new development of distribution functions that have no direct equivalent in Oracle.
- Development of Automic jobs to run DataStage pipelines and Python scripts (PySpark jobs) that control the population of the SME and institutional risk tables in the Risk Mart and perform business calculations.
- Participation in the agile process, including creating user stories, estimations, and planning in Azure DevOps.
- Handling Azure DevOps tickets and close collaboration with testers and business teams for error analysis and resolution.
Andreas I.
Last position:
Cybersecurity Specialist Assessor at Bundesnetzagentur
- Recognition of national notified bodies
- Preparation of cybersecurity competency reports
- EU Radio Equipment Directive
Kevin G.
Last position:
AI Strategy & Governance / Freelancer at Al Gambit
- Architect AI strategies and smart business processes for companies implementing AI initiatives.
- Focus on pragmatic and trustworthy AI integration delivering tangible operational value.
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
Leonid R.
Last position:
IT Business Analyst / Requirements Engineer at S-Payment GmbH / Sparkasse (DSV-Gruppe)
- Business analysis of payments for the introduction of Wero EPI in Germany.
- Analysis and optimization of merchant processes in the context of acquiring and issuing.
- Analysis of interfaces for instant payments.
- Analysis of SCT-Inst processes, settlement mechanisms and reporting processes.
- Identification and clarification of gaps in merchant processes.
- Analysis and documentation of clearing and settlement processes.
- OSPlus process analysis and documentation.
- Coordination and alignment with scheme management as well as various payment service providers and financial institutions on merchant processes.
- Preparation and follow-up as well as active participation in EPI meetings on technical coordination and regulatory topics in payments, including content familiarization and prioritization.
- Preparation and documentation of project and steering committees in the EPI environment.
- Creation of status reports for the subproject.
- Maintenance and structuring of Confluence pages for project documentation.
- Coordination and alignment with the issuing teams on individual customer processes as well as aligning with bank processes and acquirer processes in the Wero environment.
- Communication with payment service providers regarding merchant and bank processes in the Wero environment.
- Organizational support for project management in special tasks in the EPI and Wero environment.
- Digital filing and documentation in Confluence and Microsoft Teams.
- Planning, implementation and tracking of work packages and steps.
- Quality assurance and project control.
- Consulting on IT strategy, IT architecture and interface management in the EPI and Wero environment.
- Technical environment: Jira, Confluence, XML, JSON, MS Office (Word, Excel, Teams, PowerPoint), SharePoint, Draw.io, Innovator, 3rd-level support, ITIL, creation and updating of software documentation, interface management, OSPlus, Scrum, KYC, payment, European Payments Initiative (EPI), Wero, Microsoft Loop, Instant Payments, SCT-Inst.
Illia S.
Last position:
Front-End Developer at Tangram Internet Services GmbH
- IAUP (Interregional Academy of Personnel Management) commissioned the development of a distance learning system for its secondary school subdivision.
- Development of the website [link]
- Development of a billing system and integration with various payment systems
- Development of a distance learning system based on the open source Moodle solution
- Integration of the distance learning system into the user office on the [link] website
- Front-end: Vue.js v2, Nuxt.js, JavaScript, HTML, CSS, SCSS
- Back-end: LAMP (Linux, Apache, MySQL, PHP), PHP Framework Laravel, Redis, Swagger, MySQL 8.x, PayPal API
- DevOps: Docker, CI/CD, GIT
Rouven-Benjamin T.
Last position:
Operations Leader at VKB
- Operational management as well as functional and disciplinary leadership of around 34 employees (internal/external, national/international) with a budget responsibility of €2.5M
- Project management for the digital transmission of health insurance contributions
- Management of digitization projects (mainframe, CRM, databases, sales systems) with end-to-end responsibility
- Ensuring operational compliance, especially data protection and regulatory requirements
- Coordination of central interfaces between IT, procurement, finance, authorities, and customers
- Setting up and optimizing efficient organizational and governance structures
- Leading an agile team across nine operational areas
Discover over 15,000 top freelancers
Statistics of experts using JSON
Aggregated from the professional profiles of matched freelancers.
Experience
18 years (Germany: 19 years)

Position duration
2 years (Germany: 5.2 years)

Positions per freelancer
15 (Germany: 14)

Top business areas
Information Technology, Product Development, Project Management

Top industries
Information Technology, Banking and Finance, Healthcare

Certification focus areas
Information Technology, Project Management, Product Development
Bachelor's degree or higher
78% (Germany: 89%)
Master's degree or higher
43% (Germany: 56%)
Doctorate
17% (Germany: 10%)

Certifications per freelancer
5 (Germany: 2)

Most common languages
German, English, Spanish

Speak two or more languages
96% (Germany: 98%)
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 Frankfurt 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 Frankfurt using JSON
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.
JSON 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 (93%)
- Banking and Finance (71%)
- Healthcare (50%)
- Insurance (50%)
- Professional Services (46%)
- Automotive (43%)
- Transportation (39%)
- Manufacturing (39%)
Please note that freelancers can work across multiple industries, so percentages overlap.
About the technology
What JSON is
JSON, or JavaScript Object Notation, is a lightweight text format for representing structured data. Its objects, arrays, strings, numbers, booleans and null values are easy for software to parse and for people to inspect. JSON is language-independent, but it is especially common in web services and application integrations.
Where it is used
JSON carries data between browsers, mobile applications, backend services and external systems. Companies use it for API responses, configuration files, event messages, document storage and data imports. Common project work includes:
- Designing REST API request and response payloads
- Mapping JSON to databases, domain objects and user interfaces
- Transforming data between JSON, XML, CSV and other formats
- Processing nested documents and event streams
Ecosystem and tooling
Strong JSON work connects format design with the surrounding technical stack. Professionals often use JSON Schema for validation and documentation, OpenAPI for API contracts, and tools such as jq, Postman or Insomnia for inspection and testing. They may also work with JavaScript, TypeScript, Python, Java, .NET, PHP or Go libraries that serialize and deserialize JSON.
When companies need help
Freelance expertise is useful when an API contract is inconsistent, integrations fail on edge cases, or a legacy payload format needs to change without breaking clients. It also helps during platform migrations, service decomposition and the launch of partner-facing APIs. In Frankfurt, this can support regional finance, logistics, mobility and software teams working with local or distributed stakeholders.
What quality looks like
Reliable JSON is predictable, documented and safe to evolve. Experienced specialists choose clear property names, stable types and explicit rules for missing, null or optional values. They account for character encoding, date and time conventions, numeric precision, duplicate fields and unexpected input rather than assuming every payload is clean.
Working with specialists
A good brief should include sample payloads, API documentation, target systems and compatibility constraints. Ask how the professional handles schema changes, validation errors, backward compatibility and automated tests. Remote collaboration works well when examples, decisions and ownership are recorded clearly; on-site sessions in Frankfurt can help when several business and technical teams must agree on a shared contract.
Frequently asked questions
What clients ask us most about JSON — answered in short.
JSON is mainly used to exchange structured data between applications, especially through web APIs. It also appears in configuration, event processing, imports, exports and document-oriented storage.
JSON is usually more compact and maps naturally to objects and arrays used in application code. XML offers attributes, namespaces and a mature document-markup model, so the better choice depends on the integration contract, validation needs and existing systems.
A strong JSON specialist should understand REST, HTTP, API authentication and error handling. Useful adjacent skills include JSON Schema, OpenAPI, SQL or NoSQL data modeling, automated testing, and at least one application language such as JavaScript, Python or Java.
The answer depends on the work. A simple payload mapping may need limited specialist involvement, while a public API, event architecture or migration requires someone who has handled versioning, validation, security and compatibility across connected systems.
JSON projects are often well suited to remote collaboration because schemas, examples, tests and API collections can be reviewed online. Teams in Frankfurt may still prefer occasional on-site workshops when product, compliance or integration stakeholders need to settle data definitions together.
Review whether the professional provides clear schemas, realistic examples and tests for malformed and boundary-case input. High-quality JSON design uses consistent naming, explicit optional fields, useful error responses and a compatibility plan for future changes.
JSON is a strong fit for hierarchical application data and common web integrations, but it is not ideal for every workload. Large binary files, highly optimized numeric datasets, strict document publishing and streaming formats may be better served by specialized alternatives.
Before working with JSON, clarify the source and destination systems, sample payloads, schema ownership and expected compatibility rules. Also confirm how dates, numbers, null values, unknown properties, validation failures and authentication details must be handled.
The average hourly rate of freelancers in Frankfurt, Germany who have used JSON in their recent projects is 102 €, which corresponds to a daily rate of about 813 € based on an 8-hour working day.
Of the freelancers in Frankfurt, Germany who have used JSON in their recent projects, 78% hold at least a Bachelor's degree, 43% hold at least a Master's degree, and 17% hold a doctorate.
On average, freelancers in Frankfurt, Germany who have used JSON in their recent projects have 18 years of professional experience, with a single engagement typically lasting around 2 years.
The most common languages among freelancers in Frankfurt, Germany who have used JSON in their recent projects are German (100%), English (96%), and Spanish (11%).
The most common industries among freelancers in Frankfurt, Germany who have used JSON in their recent projects are Information Technology (93%), Banking and Finance (71%), and Healthcare (50%).
The most common business areas among freelancers in Frankfurt, Germany who have used JSON in their recent projects are Information Technology (100%), Product Development (75%), and Project Management (71%).
Main locations of FRATCH Experts, who have recently used JSON
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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