JSON Experts in Frankfurt
for reliable data exchange, matched in minutes with the power of AIHire experts who design clean data structures, validate APIs and connect web, mobile and enterprise systems through JSON. FRATCH finds precise matches with vetted, available freelancers who can contribute remotely or on site.
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
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)
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 client-defined requirements for existing reporting and new dashboards.
Supporting stakeholders in managing sales processes and early detection of KPI trends.
Use of Microsoft Power BI as central analysis and reporting platform.
Developing a proposal for the necessary evolution of processes and the Power BI platform.
Gathering current business processes and defining company-wide KPIs in coordination with stakeholders.
Analysis and inventory of the client's Power BI platform.
Analysis of processes and data governance.
Recording and documenting current business processes.
Developing recommendations for process and reporting platform improvements.
Designing and implementing dashboards in Power BI.
Defining company-wide KPIs and aligning them with stakeholders.
Microsoft Power BI.
Data analytics.
KPI definition and reporting.
Dashboard design and data visualization.
Stakeholder management and requirements management.
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
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
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.
Jörn B.
Last position:
Project Management and PMO at TANKKARTEN | PAYMENT
- Close collaboration with development teams to ensure alignment with project goals
- Assessment of in-scope assets, requirements definition and support of the public tender process up to vendor selection
- Creation and maintenance of UML sequence diagrams to document system interactions
- Intensive use of Agile/Scrum methodology and the Spotify model
- Development and implementation of cutover and rehearsal plans together with the application managers
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 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 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 19 Sep 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
Data format
JSON, short for JavaScript Object Notation, is a text-based format for representing structured data. Its objects, arrays, strings, numbers, booleans and null values are easy for applications to parse and for people to inspect. JSON is widely used wherever systems need to exchange clear, portable data.
Where it runs
JSON sits at the center of web APIs, mobile applications, browser services, event payloads and configuration files. It connects front-end interfaces with back-end services and supports integrations between business applications. Companies in Frankfurt use it across finance, logistics, commerce, mobility and software products that depend on reliable data flows.
Schemas and tooling
Strong JSON work includes more than writing valid syntax. Specialists use JSON Schema to describe structure, required properties and acceptable values, then apply validators and contract tests to detect breaking changes. They also work with REST and GraphQL APIs, OpenAPI documentation, command-line tools, database serializers and languages such as JavaScript, TypeScript, Python, Java and Go.
- Define consistent objects, arrays and nested relationships
- Validate payloads against JSON Schema
- Document API requests and responses with OpenAPI
- Transform data between JSON, CSV, XML and database models
When to bring expertise
Freelance expertise helps when an API is inconsistent, integrations fail at field boundaries or a product needs a stable data contract. It is also useful during migrations from XML or custom formats, when building event-driven services, or when several teams must share one evolving schema. Remote collaboration works well when examples, contracts and test cases are maintained in a shared repository.
Quality signals
A capable professional keeps payloads predictable, compact and backward compatible. They distinguish missing values from explicit null values, choose clear property names and handle encoding, dates, numbers and deeply nested structures with care. They test valid and invalid cases, document assumptions and consider security risks such as oversized payloads, unsafe data exposure and injection through downstream systems.
Delivery outcomes
The result may be a versioned API contract, a validated schema library, integration mappings, serialization logic or a test suite for exchanged payloads. Good delivery includes representative examples, clear error responses and checks that protect consumers during change. In Frankfurt, teams can combine on-site workshops with remote implementation when domain knowledge and technical ownership are clearly assigned.
Frequently asked questions
What clients ask us most about JSON — answered in short.
JSON is mainly used to exchange structured data between applications. It is common in REST APIs, browser and mobile applications, configuration files, event messages and integration workflows because it is compact, readable and supported by most programming languages.
JSON usually offers a lighter syntax and maps naturally to objects and arrays used in application code. XML provides a richer document model with attributes, namespaces and established document-oriented features, so the right choice depends on the integration, validation needs and existing systems.
A strong JSON specialist should understand HTTP, REST API design, authentication, error handling and versioning. Useful adjacent skills include JSON Schema, OpenAPI, database mapping, automated contract testing and at least one application language such as TypeScript, Python, Java or Go.
The required depth depends on the risk and scope of the data exchange. A simple mapping task needs syntax and transformation skills, while a shared API contract or migration needs experience with schemas, compatibility, testing, observability and production incidents.
JSON work is well suited to remote collaboration because schemas, examples, API specifications and tests can be reviewed asynchronously. On-site sessions in Frankfurt can help with domain discovery and decisions involving several teams, while implementation and review can continue remotely in English or German.
Review whether the payloads have clear names, consistent types, sensible nesting and documented optional fields. Ask for validation rules, invalid examples, compatibility tests and an explanation of how dates, numbers, null values, errors and sensitive data are handled.
JSON Schema is useful when multiple systems or teams must agree on the shape and constraints of exchanged data. It supports validation, documentation and contract testing, but it should be maintained with the API and versioned carefully so rules do not break existing consumers unexpectedly.
A JSON freelancer may deliver schemas, API examples, OpenAPI definitions, transformation mappings, serializer logic and automated tests. They can also review existing payloads, identify compatibility risks, improve error contracts and create guidance for teams that produce or consume the data.
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.
Berlin 
Hamburg 
Munich 
Cologne 
Stuttgart 
Dusseldorf 
Dortmund 
Essen 
Nuremberg Request a free demo
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Philipp Thomaschewski
FRATCH CEO
