JSON Experts in Hamburg
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Meet FRATCH Experts in Hamburg, who have recently used JSON
Niko Schmuck
Last position:
Developing Architect, Technical Lead "gridlytics" at HH Energienetze
- Building a data integration platform for high, medium, and low voltage assets for contextual analysis of time series with master data from the SCADA control system (IEC 60870 104), INIS, and SAP.
- Responsibility for the architecture and implementation of the solution, as well as sparring partner for the Product Owner.
- Use of Kotlin, Spring Boot, Maven, TimescaleDB, PostgreSQL, liquibase, Elements IoT, Docker, Kubernetes, Grafana, Python, jupyter, and various API gateways.
Panagiotis Tsafaridis
Last position:
Senior Data Engineer Consultant at GOLDNER GmbH
- Onboarded and conducted comprehensive documentation and system analysis to assess the existing data infrastructure, facilitating rapid integration and collaboration across functional data teams (modelling, processing, reporting).
- Collaboratively defined the architecture and project structure for a central data pipeline repository, including hierarchical standards, knowledge management strategies, and role-specific responsibilities, enhancing maintainability and onboarding speed.
- Evaluated and validated open-source data routing tools (Airbyte, Apache NiFi, Dragster) for ingest and sync requirements in retail analytics, including local benchmarking and error-state testing.
- Led the design and deployment of Airbyte in Kubernetes, creating customized Helm charts, securing secrets handling, and configuring Ingress with TLS and internal DNS routing, ensuring full API and UI accessibility.
- Troubleshot and resolved Ingress controller issues, iterating through multiple stages of debugging and testing, and documented setup and replication steps for scalable reuse.
- Mapped data models to ARTS standard, supporting schema alignment for ERP and reporting use cases, and coordinated review loops to align future data processing logic.
- Drafted strategic 1-pagers comparing MinIO, Pub/Sub, and routing architectures, providing technical guidance for architectural decisions and investment planning.
- Enabled secure access and authentication mechanisms, including initial evaluation for SAML integration, cluster-level configuration reviews, and service annotation improvements.
Hoa Josef Nguyen
Last position:
AI Architect and Enabler at Inhouse / AI Business
Technologies: n8n, Notion, OpenAI API, Claude, MS AI Foundry, MS CoPilot Studio, MS CoPilot, LLM, Node.js, Vercel, LangGraph, PostgreSQL, pgEdge, pgvector, Docker, LangChain, Ollama, Open WebUI
- Continuous evaluation and prioritization of internal automation needs
- ~20 AI agents in active use: research, content pipelines, document processing
- 5 n8n workflows for automated data and process control
- Architecture built on the same principles as in customer projects: state management, event-driven orchestration, API integration
- Ongoing operation and further development
Guido Bäcker
Last position:
Independent Management Consultant and Interim Manager at BCTC Unternehmensberatung Guido Bäcker
Consulting, training, and coaching in the financial sector on strategy, organization, and IT topics
MorgenFund: Advising the operator of a fund platform on software selection for a sub-ledger "Cash Accounts" based on Virtual IBANs (VIBAN)
Structuring requirements, market screening, creating RfIs, communicating with vendors, and conducting the selection process
UniCredit/HypoVereinsbank: Workstream lead "Booking and Customer Reporting" in the payment transformation project "PULS"
Business analysis, creating business requirements and aligning solution items as part of the functional specification with the bank's IT service providers
Business analysis of SEPA CT and SWIFT MX (.camt, .pain, and .pacs formats), change management, team lead for a virtual team of fifteen line experts, and stakeholder management
equensWorldline Germany: Program management for three projects of the SWIFT service bureau (CBPR+, ESMIG, and Euro1Step1 migration) as part of the SWIFT MX migration
Managing individual project managers regarding overarching goals and requirements; reporting to internal and external committees and stakeholders; coordinating with dependent projects and programs
Project management/PMO: interim project management, stand-in for project managers, resource planning, budget and cost management, general PMO tasks
Daniel Sedlack
Last position:
Senior Software Engineer at energielenker solutions GmbH
- Designed and implemented a Python-based ETL pipeline with the Dagster framework to transform raw energy data from heterogeneous sources using InfluxDB and visualizations in Grafana
- Defined time-based and dependency-based jobs
- Deployed to managed Kubernetes clusters using Helm
- Integrated InfluxDB Cloud
- Prepared data for use in Grafana, including cleaning, normalization, and time-based resampling in Python
- Developed dashboards and visualizations in Grafana
- Developed unit tests with mocking using pytest
- Set up a CI/CD pipeline in GitLab
Technologies: Python, Dagster, InfluxDB, Grafana, pandas, pytest, REST, CI/CD, GitLab, Container, Kubernetes, Helm, Docker, Cloud
Cornelius Höfig
Last position:
Solution Architect at STIHL
- Remodeling of the system architecture for an Azure-based platform aimed at rapid development of new functionalities
- Modeling of a staging concept for the fulfillment of diverse customer and QA needs
- Creation of requirements for, and oversight of, a proof-of-concept supplier project for a Flutter app with highly advanced BLE functionalities
- Comparison of multiple observability platforms for feasibility and requirements fit within the project environment
- Creation of a mobile app architecture based on domain-driven architecture
- Position of technical advisor and accountable solution architect for two development teams
- Execution of architecture reviews and alignment of changes with architectural expectations
- Skills & Technologies: Microsoft Azure , App Services, NodeJS Mono-repository, microservice architecture, domain driven design, self contained systems, requirements engineering, CI/CD, DevOps, API design, solution architecture
Dominic Dreiner
Last position:
Senior GEO Strategist & AI Search Consultant at Venmate GmbH
- Industry: SaaS (Customer Success Management) – B2B
Comprehensive GEO implementation (Generative Engine Optimization) for a B2B CSM SaaS startup with a focus on AI Search Visibility and AI Citations in ChatGPT, Perplexity and Google AI Overviews – including a GEO workshop and a prioritized implementation roadmap.
- GEO Workshop & Roadmap: Conceptualized and delivered a GEO workshop (how LLMs work, AI Search Architecture, citation strategies); translated it into a prioritized implementation roadmap with impact/effort estimates
- Technical GEO Foundation: Robots.txt & llms.txt, Core Web Vitals & page speed, XML sitemaps for AI crawlers
- Schema & Structured Data: Gap analysis, implementation of Product/Service, FAQ, Article, Author and Organization schema, validation of coverage
- Content Architecture & GEO: Flat content architecture, topic clusters (pillar-and-spoke), 200–300 word chunks and answer-first content structure, E-E-A-T rollout through author pages
- Query Fan-Out & Prompt Anticipation: User prompt mapping, query fan-out, content gap analysis based on prompt coverage
- Citation & Backlink Strategy: AI citation analysis (news, Reddit, Wikipedia, listicles) and development of outreach and backlink strategies
Tools & technologies: Otterly.AI, PeecAI, Qforia (iPullRank), Schema Markup Validator, OpenAI Tokenizer, Prompt Coverage Monitor, ChatGPT, Perplexity AI, Semrush, Ahrefs, Framer CMS
Rainer Diekmann
Last position:
Enterprise Architecture Management / Backend Software Developer at Polizei Hamburg
- Several projects in a police context
- Model and document police procedures/projects with Archimate (as-is/to-be) in the context of P20 (BKA)
- Create software architectures with microservices
- POC development with Springboot/Docker/Kubernetes
- Project size: 10 people
- Enterprise architecture management with Togaf and Archimate
- Backend software development Springboot
- DevOps with Kubernetes
- Implemented using: Java 17/21, Springboot 3, P20 architecture, Togaf, Archimate
Alex Odesser
Last position:
Contractor at Telefonica Germany GmbH & Co. OHG
- Data-analysis, Preparation, gathering and coordination of business requirements for retrieval of monthly- and long term (CLV – relevant) cost- and revenue-components per contract for a customer–base–grouping project (HUB–Project) for B2C-Postpaid-Controlling
- Concept and Implementation of cost- and revenue-KPIs calculation and corresponding CLV–reports (Oracle, Perl, SVN, MS SQL Server, MS Power BI, Serviceware Performance Analytics)
- Operational support of the HUB-Project – various ad-hoc reports, deployments, job-scheduling etc. (Oracle, SVN, BICSuite–Scheduler, DWSODA etc.)
- Analysis, implementation, retrieval and reporting of various physical and financial KPIs for B2P-Prepaid Business on an existing data-mart (Oracle, Perl)
Jan Gleske
Last position:
Interim Senior Application Owner for Pricing, Forecasting and Prognosis Solutions at International energy trading company
- Collaborated closely with key users, business analysts and product owners to understand requirements, define priorities and derive solutions
- Managed external service providers
- Oversaw and executed updates, patches and release management
- Handled incident, problem and change management according to ITIL
- Analyzed and evaluated incidents and changes for operational impact and business processes
- Monitored systems and interfaces, ensuring IT security and compliance requirements
- Supported IT planning, cost monitoring and contract management
- Created and executed tests for maintenance and projects
- Assisted in designing technical solutions and contributed to projects such as IT landscape harmonization and modernization
- Independently led operations-related projects and continuously optimized processes
- Achieved significant cost savings through supplier negotiations, rightsizing and decommissioning of legacy systems
- Technologies: Azure DevOps, ServiceNow, icinga, metalogic mPE/mPX, FIS, inubit, Oracle, LeanIX, One Identity, Confluence, Copilot, XML, JSON, SQL, RabbitMQ, Python, BPMN, OKR, ITIL, Kanban
Michael Kraft
Last position:
Bytec Medizintechnik
- Developed solution to filter heavily noisy analog sensor data by combining high-speed sampling with digital firmware filtering
- Increased battery life of a battery-powered medical device from about 10 days to about 18 months
- Supported the overall project up to initial clinical tests and TĂśV approval
Sascha Braun
Last position:
Fullstack Developer at INLOGY GmbH
- Developed and maintained a distributed monitoring system for drilling rigs
- Developed an administration application for the Swiss social system
- Estimated efforts for customer requirements
- Technologies: C#, ASP.NET, Entity Framework Core, MS SQL, npm, Angular, TypeScript, HTML, SCSS, Storybook, NodeJS
- Tools: Scrum, Figma, Jira, Confluence, Azure DevOps, CI/CD
Lars Kleiner
Last position:
Lead Drupal Developer at x-tention
- Lead Drupal 10 developer for several greenfield projects in the health sector
- Drupal architecture in a cloud environment
- Set up and maintain GitLab pipelines and Kustomize scripts for Kubernetes deployments
- Development of Docker images
- Developed custom Drupal modules for features such as OAuth and FHIR
- Drupal frontend theming using Bootstrap 5 and Single Directory Components
- Set up and maintain automated Playwright tests
Bilal Oguz
Last position:
Test Analyst / Test Engineer at von der Qualidence Consultancy GmbH
- Manual acceptance testing of web and Swing clients as well as mobile applications across different teams/products
- Requirements management, test analysis, and submission of review results
- Preparation and execution of smoke, regression, and user acceptance tests
- Test case design using test design techniques for user stories with acceptance criteria in XRay; import of Excel test sheets into Jira XRay
- Creation, preparation, and execution of API tests with Postman and documentation in Jira XRay
- Taking on greenfield projects for the acceptance of the web app
- Proactive collaboration with the team (developers, POs, and test manager)
- Acceptance of development and deployment of content elements on the web with TYPO3 CMS
- Tools used: Jira + XRay, Postman, Confluence, web & Swing applications, mobile app, BrowserStack, Figma, Robot Framework, Excel
Marcel Seifert
Last position:
Lead Developer / Software Architect at RezeptprĂĽfstelle Duderstadt GmbH
Responsible for the redevelopment of a billing and validation software for prescriptions to fully check and analyze e-prescriptions for correctness (content, billing)
System consists of multiple contexts running as services (Docker containers):
Checking and processing data deliveries via FTP and email
Management of invoicing, clearings, deductions and offsets
Management and execution of validation rules and test sets
Analytics based on Metabase
Developer Stack: Kotlin, Vue 3 / Vuetify 3, ANTLR, Spring Boot 3, REST API, Gradle, Docker, GitLab, PostgreSQL, Kafka, Keycloak, Scrum, Grafana, Loki, Testcontainers, Prometheus
Discover over 15,000 top freelancers
Statistics of experts using JSON
Aggregated from the professional profiles of matched freelancers.
Experience
19 years
Position duration
1.8 years (Germany: 1.9 years)
Positions per freelancer
16 (Germany: 14)
Top business areas
Information Technology, Product Development, Project Management
Top industries
Information Technology, Banking and Finance, Energy
Certification focus areas
Information Technology, Product Development, Project Management
Bachelor's degree or higher
93% (Germany: 88%)
Master's degree or higher
50% (Germany: 56%)
Certifications per freelancer
2
Most common languages
German, English, Spanish
Speak two or more languages
100% (Germany: 98%)
Based on our profile pool as of 30 Aug 2026.
Daily rate distribution
The chart shows how the daily rates of freelancers in this technology in Hamburg 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 Hamburg 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 30 Aug 2026. Actual rates may vary depending on seniority level, experience, skill specialization, project complexity, and engagement length.
About the technology
JSON at a glance
JSON, short for JavaScript Object Notation, is a simple format for structured data. Teams use it to move information between services, store settings, and exchange payloads in APIs. It is lightweight, easy to read, and easy to parse in most modern systems.
Where it fits
JSON shows up in:
- REST and web API responses
- Configuration files
- Event payloads and message queues
- Logs and telemetry exports
- Import and export pipelines
Tools and skills
Strong specialists work with parsers, validators, and schema tools. They understand JSON Schema, serialization, nesting, escaping, and character encoding. They also know when to keep documents simple so they stay stable across services and easy to maintain.
When experts help
Companies bring in freelance support when a JSON structure is breaking integrations, growing too complex, or needs a stricter contract. They also need help when one service must speak to many others without losing clarity. In Hamburg, this often matters in logistics, commerce, media, and connected systems.
What good work looks like
Good professionals write clear, predictable structures and avoid ambiguous field names. They check validation rules, edge cases, and compatibility between versions. They also review sample payloads, test data changes, and make sure teams handle missing or optional fields the same way.
Collaboration and delivery
JSON work is often remote, because reviews happen in files, APIs, and shared examples. On-site collaboration can help when teams need to align on data contracts, handoff rules, or system boundaries. The best specialists keep communication precise and make changes easy for both technical and non-technical teams.
Frequently asked questions
Key details about JSON, drawn from the questions we get asked most.
A strong JSON specialist helps with API payloads, configuration files, schema validation, and data exchange between services. This work is common when systems need a clean contract and teams want fewer parsing errors or broken integrations.
JSON is usually chosen for machine-readable data that must travel fast between services. Compared with XML, it is shorter and simpler; compared with YAML, it is often safer for APIs because its rules are stricter and less ambiguous.
JSON alone defines the data shape, but it does not enforce rules by itself. If a project needs validation, required fields, type checks, or versioned contracts, JSON Schema becomes important very quickly.
A good JSON freelancer usually understands REST APIs, JavaScript, backend services, and data validation. In many projects, experience with OpenAPI, message queues, and testing tools is also useful.
Simple data formatting tasks can be handled quickly, but complex integration work needs someone who knows edge cases and compatibility issues. The right JSON expert is the one who has worked with real API contracts, not just basic file editing.
Most JSON work can be done remotely because the deliverables are usually files, schemas, and API examples. On-site sessions help when several teams must agree on naming, payload structure, and system boundaries.
Look for clean structure, consistent naming, clear validation rules, and careful handling of optional or missing fields. A strong JSON professional explains trade-offs, spots breaking changes early, and writes data that other teams can trust.
In many systems, JSON is still the default choice for APIs, microservices, and configuration because it is easy to read and widely supported. It may not fit every use case, but for most web and service integrations it remains a practical option.
The average hourly rate of freelancers in Hamburg, 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 Hamburg, Germany who have used JSON in their recent projects, 93% hold at least a Bachelor's degree and 50% hold at least a Master's degree.
On average, freelancers in Hamburg, Germany who have used JSON in their recent projects have 19 years of professional experience, with a single engagement typically lasting around 1.8 years.
The most common languages among freelancers in Hamburg, Germany who have used JSON in their recent projects are German (100%), English (100%), and Spanish (16%).
The most common industries among freelancers in Hamburg, Germany who have used JSON in their recent projects are Information Technology (89%), Banking and Finance (58%), and Energy (53%).
The most common business areas among freelancers in Hamburg, Germany who have used JSON in their recent projects are Information Technology (100%), Product Development (74%), and Project Management (68%).
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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