
JSON Schema Experts in Germany
for reliable APIs, data contracts and validation, matched in minutesHire experts who design maintainable schemas, validate API payloads and connect JSON Schema with OpenAPI, TypeScript and automated tests. FRATCH quickly matches you with vetted, available freelancers whose experience fits your project.
Meet FRATCH Experts in Germany, who have recently used JSON Schema
Collin K.
Last position:
Software Architect / Fullstack Developer at Equity Bytes
Built an international e-commerce platform for a multi-vendor marketplace for digital assets from scratch. Designed and operated cloud native architectures at enterprise scale.
- Designed and operated a highly scalable microservice and serverless architecture
- Built the complete cloud infrastructure with Terraform + AWS CDK in AWS
- Provisioned ECS/EKS clusters (Fargate), Application Load Balancers (reverse proxy), and Lambda functions
- Observability & tracing with CloudWatch, DataDog, Prometheus, and Grafana
- End-to-end setup with DataDog (formerly AWS CloudWatch), Prometheus, and custom Grafana dashboards
- Integration of advanced metrics (including ORM mapper) and distributed tracing with Jaeger
- Robust backup and disaster recovery strategies
- RDS Postgres backups and hourly snapshots
- Read-only, asynchronously synchronized replicas with automated master failover in emergencies
- Minute-level rollback capability through versioned Docker images on ECS and Git-based CI/CD pipelines
- Created CI/CD pipelines with GitHub Actions for automated multi-stage deployments (Dev, Testing, Prod)
- Integrated Stripe for international payment processing
- Built a marketplace payment system with multiple parties and payout routines
- Used Algolia for high-performance real-time search of digital assets on the platform
- Federation of services with GraphQL and Hasura
- Later migration to GraphQL Mesh
- Test Driven Development (TDD) - unit, integration, and E2E testing with Jest, Vitest, and Playwright
- Used Next.js / React for modern frontend applications in the nx monorepo
- Enterprise security architecture & access control
- Integration of JWT tokens with Auth0, OAuth, OIDC, IP guards, BOLA protection, and secret vaults
- Authorization concepts with RBAC, ABAC, and native Postgres Row-Level Security (RLS)
- Built internal microfrontends with Retool for fast prototyping and operational business processes
Technologies: ABAC, AWS CDK, AWS CloudWatch, AWS ECS, AWS EKS, AWS Fargate, AWS RDS, AWS S3, Algolia, Auth0, DataDog, Docker, GitHub Actions, Grafana, GraphQL, GraphQL Mesh, Hasura, JWT, Jaeger, Java, JavaScript, Jest, Kotlin, Kubernetes, Monorepo, Next.js, OIDC, Playwright, Postgres, Postgres RLS, Prometheus, RBAC, Redis, Retool, Serverless, Stripe, Terraform, TypeScript, Vitest
Giovanni L.
Last position:
Solution Architect at Nordea Bank
Consumer Cards Solution Architect
- Provided architectural leadership in Consumer Cards Domain establishing best practices and improving architectural transparency and maintainability by designing a structured documentation framework to enable reverse engineering of legacy card systems.
- Standardized architectural artefacts including BIAN Business Capabilities, UML diagrams in draw.io format (Use Case, Component, Sequence), naming conventions, document repository, design templates and blueprints, microservices.
- Produced high-level and low-level designs aligned with enterprise architecture governance processes and artefact standards.
- Provided architectural support to the Strategic Card Simplification Programme, focusing on card product migrations and application decommissioning across all countries. Agile environments (Scrum/SAFe).
- Analysed and designed AI use cases in the architecture domain.
Project: Payment Card Industry Data Security Standards (PCI DSS) Strategic Programme
- Analysed and documented existing data flows across card products and geographic regions to assess PCI DSS compliance.
- Identified areas involving sensitive data at rest and data in motion requiring encryption or masking, ensuring adherence to PCI DSS requirements.
- Collaborated with security, infrastructure, and application teams to align encryption strategies with regulatory and organizational policies.
- Provided strategic advisory services on data strategy, data governance, data management, data quality, data architecture, data mesh, MEGA HOPEX, DAMA-DMBOK, event-driven architecture, end-to-end data flows and card product harmonization models.
- Ensured solution design alignment with regulatory compliance (BCBS 239, DORA, GDPR) and internal policies.
Project: Denmark ATM Outsourcing Project
Objective: Outsource ATM operations and maintenance to a third-party provider while expanding the Denmark ATM fleet, with Nordea retaining ownership of ATMs and cash for the existing and extended infrastructure.
- Led a cross-functional delivery team (project management, business analysis, and architecture) and documented the as-is ATM ecosystem architecture, including end-to-end data flows, integrations, and internal/external application interfaces.
- Designed end-to-end processes for authorization, reconciliation, and settlement, aligning operating model, controls, and compliance requirements across Nordea and the outsourced service provider.
- Produced high-level and low-level solution designs using standardized UML artefacts (Use Case, Component, and Sequence diagrams) to support vendor onboarding, integration planning, and implementation.
- Ensured architectural alignment and decision-making across enterprise stakeholders and third-party providers, managing dependencies and interfaces in the context of the outsourcing initiative.
Muhammed D.
Last position:
Software Engineer at The.NextGen GmbH
- Created internal web application to improve the salary process using a microservice interfacing with MSSQL
- Developed interactive web UI using Microsoft Blazor
- Integrated Azure AD for user authentication
- Designed and implemented roles and permissions in the database
- Developed progress page guiding users through each process step
- Processed bonus calculations by importing Excel files
- Configured email notifications using MSSQL Send Mail
- Tools and technologies: C#, ASP.NET 6, MS-SQL, REST API, Visual Studio 2022, TFS, microservices, Kanban Board, Azure DevOps
Markus O.
Last position:
Lead E-Solution Architect & Senior Requirements Engineer at Zasterbot-Oracle
- Clarification of project goals, scope, and functional target vision for building the AI-based knowledge base.
- Deriving the initial architecture and implementation strategy for the Zasterbot chatbot, including defining the MVP and expansion phases.
- Developing a functional target vision for building a structured knowledge base and integrating a future chatbot.
- Deriving and prioritizing use cases for information retrieval and provision by the chatbot.
- Modeling data structures and flows for effectively organizing the knowledge base on the Base44 platform.
- Designing and implementing data models for storing and linking relevant information.
- Developing processes for extracting, analyzing, and preparing raw data for the knowledge base.
- Ensuring data consistency and quality as the foundation for the future chatbot.
- Planning the integration of large language models (LLMs) and retrieval-augmented generation (RAG) for precise and context-aware responses.
- Implementing features for analyzing and visualizing data from the knowledge base.
- Using the Base44 platform with JSON-schema-based entities and a flexible permission model.
- Implementing Deno functions for backend logic, event processing, and external API integration.
- Integrating OpenAI services for initial data analysis.
Michael M.
Last position:
Deutsche Bahn
- Implemented accessibility audit recommendations for the ICE onboard portal to improve usability for screen reader and keyboard users
- Migrated end-to-end tests from Cypress to Playwright
- Refactored components to meet accessibility standards
- Introduced Prettier for consistent code formatting
Franck F.
Last position:
Multiproject Manager / Senior Business Analyst at MANN&HUMMEL
- Overall management of several project streams: mechanical development, IoT integration, software development, plant design, validation
- Management of an international project team made up of mechanical engineers, electronics engineers, software developers, designers, and external suppliers
- Coordination of global stakeholders from Germany, France, India, China, and the USA
- Planning, controlling, and reporting across all project levels: schedule, budget, resources, and deliverables (PMI-oriented)
- Moderation of steering committees, technical workshops, and milestone decisions
- Responsibility for requirements management and prioritization in the overall context (IoT, cloud, mechanical integration, safety standards)
- Quality assurance and test strategy: validation of filtration results, system behavior, plant integration
- Supplier management and procurement involvement for components, logistics, and assembly
- Risk management and escalation handling for technical, regulatory, or cross-country deviations
- Go-to-market preparation: coordination of product documentation, CE certification, training, and handover to service & sales
- Methods: multiproject management according to PMBOK, hybrid model SCRUM + classic milestone planning, stage-gate model
- Tools: MS Project, Excel, Jira, Confluence, Miro, MS Teams, SharePoint, CAD/CAE systems, test and validation software
- Technologies: OPC UA, MQTT, Siemens S7, IO-Link, Modbus, REST APIs, SCADA, monitoring dashboards, sensors & control technology, CE-compliant housing design, ISO standards
Daniel C.
Last position:
Founder & Managing Director at BotCraft GmbH
- Building the company with a focus on connectivity for IIoT and Industry 4.0, iRPA/process automation, advanced robotics and smart systems, sensors and services
- Project management and software architecture for IoT gateway development (since 2020) with protocol translation, IT/OT convergence and GRC
- Developing RPA bots for automating and monitoring industrial processes with an agent-based AI approach (since 2020)
- Implementing unsupervised clustering and anomaly detection for time series data in big data streaming pipelines (since 2021)
- Introducing a Docker-based release train for OTA updates with DevSecOps and CI/CD (since 2018)
Katharina S.
Last position:
AI Engineer
- Designed and implemented end-to-end automated workflows for extracting structured data from semi-structured PDF documents including invoices and medical reports
- Leveraged Optical Character Recognition (OCR) technology and large language models to parse documents and generate validated JSON schemas
- Engineered prompt optimization strategies and rule-based classification hierarchies to enhance parsing accuracy across diverse document layouts
- Established quality assurance framework using evaluation metrics to validate output against ground truth datasets with 96% accuracy
Jan B.
Last position:
API-Engineer at Freelance
- API-first product design (OpenAPI 3, HAL) and development (NodeJS)
- Setting up DevOps pipelines with GitHub Actions in an AWS architecture
- Technologies: OpenAPI 3, REST, HAL, NodeJS, JavaScript, TypeScript, AWS, AWS Lambda, Docker, GitHub Actions
Adithya N.
Last position:
Vehicle Classification and Detection using Neural Networks
Detecting and classifying vehicles in images and video for traffic monitoring
- A YOLO + Faster R-CNN model built for real-world traffic and autonomous-vehicle scenarios. Awarded Best Paper Award at St Joseph Engineering College, March 2025.
What it does
- The model takes images or video frames and both localizes and classifies vehicles by type, making it usable for downstream applications such as traffic-flow monitoring or perception in autonomous-vehicle systems.
What I did
- Combined YOLO (for fast detection) with Faster R-CNN (for higher-precision classification), rather than relying on a single architecture, trading off speed and accuracy where each mattered most.
- Achieved 90% mean Average Precision (mAP), evaluated using IoU-based metrics rather than just raw accuracy, to properly reflect localization quality.
- Handled the full data processing and evaluation pipeline in Python using TensorFlow and OpenCV.
- The accompanying paper was awarded the Best Paper Award by the Department of CSE at St Joseph Engineering College.
Tech stack: Python, TensorFlow, OpenCV, YOLO, Faster R-CNN
Georg L.
Last position:
Solectrus
- Dashboard application for visualizing power generation and consumption as well as profitability calculations for a photovoltaic system.
- The software is built in a strictly modular way and can be used in many different settings, including on devices like the Raspberry Pi or NAS systems, and offers connection options for a wide range of PV systems.
- A steadily growing community values the intuitive operation and the high reliability of the tool.
- The source code is open source, and development is funded through a sponsorship model.
- Technologies: Ruby on Rails, InfluxDB, Docker, MQTT
Markus T.
Last position:
Senior Software Engineer at Krauss Maffei Technologies GmbH
- Architecture and design of the application
- Development of new features
- Integration with AWS backend (GraphQL, REST)
- Deployment on AWS
- Gatsby, React, Redux, Material UI, TailwindCSS, ChartJS, Plotly, GraphQL, GitLab
Matthias M.
Last position:
Founder at CaseOS Low-Code Platform
Discover over 15,000 top freelancers
Statistics of experts using JSON Schema
Aggregated from the professional profiles of matched freelancers.
Experience
16 years

Position duration
2.7 years

Positions per freelancer
10

Top business areas
Information Technology, Product Development, Research and Development

Top industries
Information Technology, Automotive, Insurance

Certification focus areas
Information Technology, Marketing, Product Development
Bachelor's degree or higher
91%
Master's degree or higher
73%
Doctorate
9%

Certifications per freelancer
1

Most common languages
English, German, French

Speak two or more languages
100%
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 Germany 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 Germany using JSON Schema
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 Schema 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%)
- Automotive (46%)
- Insurance (46%)
- Professional Services (46%)
- Banking and Finance (38%)
- Healthcare (38%)
- Education (31%)
- Transportation (31%)
Please note that freelancers can work across multiple industries, so percentages overlap.
About the technology
What JSON Schema does
JSON Schema is a vocabulary for describing the structure, types, constraints and relationships of JSON data. It lets teams validate requests, responses, configuration files and event payloads against a shared contract. The JSON Schema specification improves clarity between services, front ends and external integrations without prescribing a programming language.
Where it is used
- Define contracts for REST and event-driven APIs
- Validate incoming data before processing
- Document configuration and integration formats
- Generate forms, types and reference documentation
- Test payloads across distributed services
JSON Schema appears in SaaS products, finance, logistics, healthcare and public-sector systems. In Germany, specialists often support multilingual teams that need dependable data exchange across internal systems and suppliers.
Ecosystem and tooling
The work commonly connects JSON Schema with OpenAPI, AsyncAPI, TypeScript, Java, Python, JavaScript and .NET. Specialists select validators such as Ajv or language-specific libraries, manage reusable definitions, and integrate checks into build pipelines. They may also work with schema registries, code generation, API gateways and documentation tools.
When expertise matters
Companies bring in freelance expertise when schemas are inconsistent, validation is missing or a growing API needs a stable contract. Specialists can review an existing schema model, introduce compatibility rules, migrate draft versions and align producers with consumers. They also help teams decide where validation belongs and how errors should be returned.
- Establish a schema governance approach
- Resolve breaking changes between services
- Add validation to CI and contract tests
- Map legacy payloads to a consistent model
What strong specialists deliver
Strong professionals understand data modeling rather than treating a schema as a list of fields. They use required properties, enums, formats, references, conditional rules and composition carefully. They explain trade-offs around strictness, backward compatibility and unknown properties, then leave readable schemas with useful examples and actionable validation errors.
Working with specialists
JSON Schema work is often suitable for remote collaboration because schemas, pull requests and test fixtures are easy to review asynchronously. On-site workshops can help when domain rules are unclear or several German business units share one contract. Agree on repository access, review language, naming conventions and ownership before implementation starts.
Frequently asked questions
What clients ask us most about JSON Schema — answered in short.
Companies use JSON Schema to describe and validate JSON documents, API requests, responses, events and configuration files. It creates a shared contract that can be checked automatically before data reaches business logic.
JSON Schema focuses on validating JSON data and expressing its constraints. OpenAPI uses schemas within a broader API description, while TypeScript types mainly support compile-time checks in TypeScript applications; many teams use them together.
A strong JSON Schema specialist usually understands REST APIs, OpenAPI or AsyncAPI, version control and automated testing. Experience with Ajv, code generation, TypeScript, Python, Java or .NET can also be valuable, depending on the system.
The right level depends on the scope. A simple validation rule may need focused schema knowledge, while shared contracts across services require experience with versioning, references, compatibility and consumer-driven tests.
Yes. JSON Schema projects are well suited to remote work through repositories, pull requests, schema reviews and automated validation. On-site sessions may still help when specialists must clarify domain rules with several German teams.
Ask how the specialist handles nested structures, reusable references, conditional validation and backward-compatible changes. Review whether examples are meaningful, errors are clear and schemas are tested against valid and invalid payloads.
JSON Schema can support evolving APIs when teams define compatibility rules and review changes against real consumers. A specialist should distinguish additive changes from breaking ones and connect schema checks with contract or integration tests.
Maintainable JSON Schema uses consistent naming, focused definitions, clear descriptions and deliberate reuse. It avoids unnecessary complexity, documents formats and assumptions, and keeps validation behavior aligned with the services that produce and consume the data.
The average hourly rate of freelancers in Germany who have used JSON Schema in their recent projects is 102 €, which corresponds to a daily rate of about 817 € based on an 8-hour working day.
Of the freelancers in Germany who have used JSON Schema in their recent projects, 91% hold at least a Bachelor's degree, 73% hold at least a Master's degree, and 9% hold a doctorate.
On average, freelancers in Germany who have used JSON Schema in their recent projects have 16 years of professional experience, with a single engagement typically lasting around 2.7 years.
The most common languages among freelancers in Germany who have used JSON Schema in their recent projects are English (100%), German (92%), and French (31%).
The most common industries among freelancers in Germany who have used JSON Schema in their recent projects are Information Technology (100%), Automotive (46%), and Insurance (46%).
The most common business areas among freelancers in Germany who have used JSON Schema in their recent projects are Information Technology (100%), Product Development (100%), and Research and Development (54%).
Main locations of FRATCH Experts, who have recently used JSON Schema
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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