JSON Expert in Dusseldorf
for reliable data exchange, matched in minutes from over 15,000 CVsHire experts who design data structures, validate API payloads and connect web, mobile and backend systems through JSON. FRATCH matches you quickly and precisely with vetted, available freelancers who fit your technical and project needs.
Meet FRATCH Experts in Dusseldorf, who have recently used JSON
Saruna M.
Last position:
Master's Thesis at Heinrich Heine Universität
- Title: Enhancing Syntactic Awareness in Transformer Language Models for Hindi Dependency Parsing
- Investigated syntactic knowledge captured by transformer language models (RoBERTa, XLM-RoBERTa) for Hindi dependency parsing, a morphologically rich and low-resource language.
- Developed structure-aware model variants (Struct_Roberta_hi, Struct_XLMR) by integrating a CNN-based parser network between transformer layers, inspired by the StructFormer architecture.
- Conducted extensive error analysis including label-wise, distance-based, direction-based, sentence length-based, and LVC/Non-LVC evaluations.
- Evaluated models on downstream NLP tasks (NER, POS tagging) using the IndicXTREME benchmark.
Lutz E.
Last position:
Freelance Software Developer – GoPro MultiCam Control via COHN at Plutos Company UG
- Development of a pilot system to control and monitor multiple GoPro cameras
- Implementation of start, stop, status, media, download, and diagnostic functions via COHN endpoints
- Realization of camera detection, single and group control, as well as stable session/keep-alive logic
- Setup of a download pipeline with queue, retry handling, and temporary files
- Consistent session, folder, and file naming for multi-camera recordings
- Integration of provisioning, certificates, and network operations
Stanislaus S.
Last position:
Security Consultant at Rohde & Schwarz AG at Star Labs GmbH
- Worked on FPGA enhanced network encryption device with secure boot, TPM2.0 and smart card integration for BSI approved usage with Post Quantum Cryptography
- Developed and audited Linux drivers
- Collaborated using GitLab, Gerrit, Confluence and Jira
- Technologies: C, C++, Secure Boot
Alexander R.
Last position:
Business Analyst at Financial Services Provider Landesbank
The Helaba ATLAS project aims to modernize core systems and make them future-proof. As part of the subproject, the existing legacy system for international payments is being replaced by a modern web-based application.
- Analysis of functional and technical requirements
- Analysis and optimization of business processes
- Process modeling
- Preparation and facilitation of workshops
- Defining project scope and prioritizing requirements
- Business process management (analysis, modeling, and optimization)
- Specification of user stories
- Designing business and authorization concepts
- Testing and acceptance
- Designing mockups in Figma
- Creating the UI/UX style guide for web applications Approach: Scrum (agile) Technologies: Jira, Confluence, MS Teams, Conceptboard, Java, Vaadin, Figma
Peter H.
Last position:
Product Owner / Senior Business Analyst
- Analysis of the possibility of transferring market location data to a separate microservice in an overarching web portal
- Development of a more user-friendly target process based on the current process in coordination with users
- Coordination of the related architecture concept with architects/developers
- Coordination of the related epics and user stories with the relevant business departments
- Backlog prioritization and project planning (including effort estimation)
- Testing and acceptance of implemented user stories
- Technologies/tools used: MS Office, Jira, Mural, Kotlin, React, GitHub, MS Azure, SQL, Postman, XML, JSON, Kafka, Balsamiq, BPMN
Sebastian C.
Last position:
Public institution responsible for educational institutions in NRW
- Consulting on processes and execution of load tests, performance tests and technical tests of various applications: web portal, file cloud, email, video conferencing, learning/course platform
- Creating the load test framework
- Programming test scripts (JMeter, Selenium)
- Developing batches to support the evaluation
- Executing load tests and evaluating results, including clear reporting, recommendations for action, and bottleneck analysis
- Managing tasks and collaboration to achieve meaningful load test results
Anouar T.
Last position:
Fullstack Developer Java/Spring Boot at Snipes SE (Deichmann Group)
- Migration of a .NET Core loyalty program for Snipes, used by mobile cash registers in Snipes stores
- Part of the customer’s digitalization strategy in an agile, cross-functional team with a high level of ownership
- Connecting interfaces to third-party systems (e.g. Brandung, CDS)
- Quality assurance through automated tests
- Carrying out developer, unit, and integration tests
- Patterns & methods used: Clean Code, microservice architecture, agile development with SCRUM
- Technologies & tools used: Spring Boot, Java 23, Java Persistence API (JPA), Azure DevOps, Azure Key Vault, Azure PostgreSQL, Docker & Kubernetes, Git, Graylog, Grafana, JUnit, SonarQube, Jira, Confluence, Prometheus, GitLab, GitLab CI/CD, Visual Studio Code
Nils S.
Last position:
Backend system and web client for exchanging electricity meters for utility providers at Freelance
Design and implementation of a system to control the entire process for new, removal, and exchange operations of electricity meters by external service providers for a utility company
Automated retrieval of orders and available devices via defined interfaces (e.g. from SAP)
Orchestration of process steps (assigning meters, processing meter data, sending updated information back to the source system) using a Spring Boot backend
Provision of a React-based web client for operational tracking and control of orders, e.g. to continue failed process steps or resend notifications
Jürgen V.
Last position:
Instructor / Trainer at SAP Training Company
- Instructor / Trainer
- SAP applications in SAP S/4 HANA - Sales, Sourcing Procurement, Logistic Execution, SAP Foundation
- SAP S/4 HANA - Fiori UX and Fiori Launchpad
- Cross-module MM application - Sourcing & Procurement
- Business processes SAP S/4 HANA Procurement
- Purchasing processes SAP S/4 HANA MM
- Incoming processes SAP S/4 HANA MM
- Supplier invoicing SAP S/4 HANA MM
- Pricing & plant determination SAP S/4 HANA MM
- Automation in SAP S/4 HANA MM
- Business processes SAP S/4 HANA Pre & After Sales
- Sales processes SAP S/4 HANA Sales
- Delivery processes SAP S/4 HANA Sales
- Billing SAP S/4 HANA Sales
- Pricing SAP S/4 HANA Sales and Storage Rooms and Lean-EWM
- Automation in SAP S/4 HANA Sales
- SAP S/4 HANA – SAP Private Cloud – Release 2023
Çağrı S.
Last position:
Freelance Art Director / Motion Designer at 12yapım
- Direct and produce a monthly AI-generated Reels series for a retail client — 7 episodes completed, now running at 2/month.
- Own the full pipeline: direct visual prep, write JSON prompts for AI video generation, finalize cut, color, and sound.
- Deliver each video in 2-3 days from brief to final.
Jacqueline H.
Last position:
Kitchen Appliance Manufacturer
Setting up and enhancing an international subscription management system
Migrating and decommissioning a Hybris-SAP system and integrating Zuora
Implementing numerous interfaces to various systems (external and internal)
Setting up and improving monitoring with Grafana, Prometheus, and Databricks
Introducing logging with Loki
Implementing business requirements using jQuery, Thymeleaf, Spring Boot, Java, Go, and Python
Adjusting and extending the GitLab CI pipelines
Setting up and extending infrastructure as code with Terraform and ArgoCD on AWS
Setting up and running E2E and performance tests
Expanding the Databricks business intelligence solution to provide various KPIs
Responsibilities: Architecture, DevOps, development, unit tests, coaching employees and apprentices, E2E, smoke, and integration tests, agile methods consulting (Kanban, Scrum)
Technologies and methods: Java, Go, Kotlin, Node.js, Spring Boot, SOAP/REST, Quarkus, Thymeleaf, Vaadin, Slack, Jira, Confluence, IntelliJ, GitLab, SQS, Kafka, AWS, Kubernetes, Terraform, Maven, Gradle, GitLab CI, Databricks
Daniel M.
- SaaS including subscription management and mobile app
Discover over 15,000 top freelancers
Statistics of experts using JSON
Aggregated from the professional profiles of matched freelancers.
Experience
17 years (Germany: 19 years)
Position duration
1.2 years (Germany: 5.2 years)
Positions per freelancer
14
Top business areas
Information Technology, Product Development, Business Intelligence
Top industries
Information Technology, Retail, Banking and Finance
Certification focus areas
Information Technology, Product Development, Project Management
Bachelor's degree or higher
100% (Germany: 89%)
Master's degree or higher
75% (Germany: 56%)
Doctorate
13% (Germany: 10%)
Certifications per freelancer
3 (Germany: 2)
Most common languages
German, English, French
Speak two or more languages
100% (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 Dusseldorf 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 Dusseldorf 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 (100%)
- Retail (67%)
- Banking and Finance (58%)
- Manufacturing (50%)
- Professional Services (42%)
- Automotive (33%)
- Education (33%)
- Media and Entertainment (33%)
Please note that freelancers can work across multiple industries, so percentages overlap.
About the technology
What JSON does
JSON, short for JavaScript Object Notation, is a lightweight text format for representing structured data. It is easy for people to read and for software to parse, which makes it a standard choice for communication between browsers, mobile apps, services and databases. JSON is language-independent, even though its syntax comes from JavaScript.
Where it is used
JSON appears across modern digital products and connected services:
- REST and GraphQL API requests and responses
- Configuration for applications, tools and cloud services
- Data exchange between frontend and backend systems
- Event payloads in message queues and serverless workflows
- Document storage and import or export processes
Its flexibility suits fast-moving products, while clear schemas and validation keep integrations dependable as systems evolve.
Ecosystem and tooling
Strong JSON specialists work with API specifications such as OpenAPI and JSON Schema, alongside HTTP, authentication and common serialization libraries. They may use tools such as Postman, curl, jq and language-specific parsers to inspect, transform and test payloads. Knowledge of JavaScript, TypeScript, Python, Java, PHP or .NET is often relevant because JSON crosses language and platform boundaries.
When companies need expertise
Freelance expertise is useful when an integration is unreliable, a public API needs a consistent contract or several teams exchange incompatible payloads. Specialists help with migration from XML or CSV, schema design, validation rules, performance issues and backward compatibility. In Dusseldorf, they can support local product, logistics, industrial and commerce teams either on site or remotely, depending on collaboration needs.
What strong specialists deliver
A capable professional treats JSON as a contract rather than an unstructured text blob. They choose clear names and types, define required and optional fields, handle null values deliberately and document changes. They also understand security concerns such as excessive payload exposure, unsafe parsing and sensitive data in logs. Their work includes tests, examples and monitoring so other teams can use the interface with confidence.
Choosing the right professional
Look for evidence of integrations that cross application boundaries, not only experience formatting objects. Ask how the specialist handled versioning, validation failures, malformed input and changing requirements. Strong professionals can explain trade-offs between compact payloads and readability, align JSON Schema with real business rules and communicate clearly with teams working in different languages. Remote collaboration works well when API contracts, sample payloads and decisions are documented; on-site work may help when systems and stakeholders are closely connected.
Frequently asked questions
Need clarity? These are the questions we hear most often about JSON.
JSON is mainly used to exchange structured data between applications, especially through web APIs. It also supports configuration files, event messages, document storage and data transfers between services.
JSON is usually more compact and easier to work with in web and JavaScript-based applications. XML offers richer document features and established tooling for some enterprise, publishing and highly formal data workflows, so the right choice depends on the integration.
A strong JSON specialist should understand HTTP, REST, authentication, API documentation and schema validation. Experience with JSON Schema, OpenAPI, databases, testing tools and at least one backend or frontend language is also valuable.
The scope matters more than the format itself. A simple payload change may need focused support, while a specialist handling a shared API contract should be comfortable with versioning, validation, error handling, security and coordination across teams.
Yes, JSON work is often well suited to remote collaboration because schemas, sample payloads and API tests can be shared digitally. On-site sessions in Dusseldorf can still help when specialists need direct access to internal systems or close contact with product and operations teams.
JSON is a better fit when data has nested objects, relationships, optional fields or must be exchanged by software through an API. CSV remains useful for flat tabular data and straightforward spreadsheet or bulk-import workflows.
Review whether the JSON structure is consistent, documented and validated against clear business rules. Good work includes meaningful names, predictable errors, tested edge cases, safe handling of sensitive fields and a compatibility plan for future changes.
Freelancers working with JSON often contribute across application boundaries rather than inside one product layer. They may define contracts, troubleshoot integrations, transform data, improve tests and explain trade-offs to teams using different programming languages.
The average hourly rate of freelancers in Dusseldorf, Germany who have used JSON in their recent projects is 100 €, which corresponds to a daily rate of about 799 € based on an 8-hour working day.
Of the freelancers in Dusseldorf, Germany who have used JSON in their recent projects, 100% hold at least a Bachelor's degree, 75% hold at least a Master's degree, and 13% hold a doctorate.
On average, freelancers in Dusseldorf, Germany who have used JSON in their recent projects have 17 years of professional experience, with a single engagement typically lasting around 1.2 years.
The most common languages among freelancers in Dusseldorf, Germany who have used JSON in their recent projects are German (100%), English (100%), and French (17%).
The most common industries among freelancers in Dusseldorf, Germany who have used JSON in their recent projects are Information Technology (100%), Retail (67%), and Banking and Finance (58%).
The most common business areas among freelancers in Dusseldorf, Germany who have used JSON in their recent projects are Information Technology (100%), Product Development (100%), and Business Intelligence (58%).
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 
Frankfurt 
Stuttgart 
Dortmund 
Essen 
Nuremberg Request a free demo
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Philipp Thomaschewski
FRATCH CEO
