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JSON Experts in Berlin

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Hire experts who design clear data contracts, connect REST and GraphQL services, and validate complex payloads with JSON Schema. FRATCH matches you quickly and precisely with vetted, available freelancers.

Meet FRATCH Experts in Berlin, who have recently used JSON

Verified expert

Vili D.

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Senior Data Engineer, Data Architect, Software Developer

Neuenhagen
Vili D.

Last position:

Technical Lead, Data Engineer at Mercedes-Benz Consulting

  • Optimized the data architecture (Medallion) to better decouple processing steps and improve transparency and reproducibility

  • Ensured the technical quality of data processing in Databricks by introducing schema enforcement, data quality checks, and a structured data architecture

  • Pipeline orchestration with Azure Data Factory

  • Improved and automated the development and deployment process by integrating Git and GitHub Actions

  • Technical leadership of the Data Engineering team (3 employees)

  • Led workshops to optimize and stabilize the data platform and development process

  • Collected and prioritized new requests and maintained the product backlog

  • Technologies: Microsoft Azure (Data Lake, Data Factory), Databricks, Apache Spark (PySpark), Python, SQL, Git, Confluence, Power BI, Power Apps, Dataverse, MS Sharepoint, Mural

Verified expert

Imran A.

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Software Engineer II

Berlin
Imran A.

Last position:

Software Engineer II at LivePerson Germany GmbH

  • Led development of 15+ microservices (Java 17, Spring Boot) driving customer interactions; migrated from on-prem to GCP Kubernetes, improving scalability and reducing infra cost by 20%.
  • Optimized user services with CouchDB caching and API refactoring, cutting response times by 35% and enhancing customer experience.
  • Implemented canary deployments, FluxCD GitOps, and CI/CD optimizations in GitLab, reducing release lead time by 25% and enabling zero-downtime rollouts.
  • Set up Grafana health checks and Anodot alerts for latency, error, and throughput monitoring, reducing MTTR by 40%.
  • Built secure APIs using OAuth2, DPoP, and Gatekeeper, integrated REST and GraphQL, and achieved 90%+ test coverage with unit and E2E tests.
  • Mentored junior developers, promoted Agile best practices, and collaborated cross-functionally to deliver high-impact, reliable customer-facing features.
Verified expert

Rüdiger S.

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Full-Stack Software Engineer / Consultant for Digitalization

Berlin
Rüdiger S.

Last position:

Full-Stack Software Engineer / Consultant for Digitalization at ARTEVENT

  • Designed, built, and launched an internal event planning web application used by over 100 department leads for a large event, despite having no dedicated testing phase.

  • Ensured smooth, failure-free operation during first production use, leading to the tool being adopted for future events.

  • Automated catering calculations and related workflows, significantly reducing email communication and manual computation effort for meal planning.

  • Managed deployment and hosting on a Linux server using Coolify, including application setup and runtime operations.

  • Hired and guided a communication designer on UX while independently owning all technical decisions and implementation.

Verified expert

Marvin M.

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AI Engineer & Architect · LLM and Multi-Agent Systems

Berlin
Marvin M.

Last position:

Co-founder & CTO · Freelance Software Engineer (AI & SaaS) at Self-employed

  • Self-employed · Berlin, Germany
  • Co-founded the company and own the entire technical side: product architecture, backend, frontend, infrastructure and operations.
  • Designed and built the Automated Booking System (ABS) as well as the core platform and payment logic.
  • Development of AI-powered SaaS products, from architecture through backend and frontend to production operation.
  • Technical consulting on product architecture, data protection and permissible automation.
  • Building, running and monetising my own API products for AI agents, each available as a REST interface and as an MCP server.
  • Full ownership of architecture, infrastructure, billing, legal texts and go-to-market.
Verified expert

Hamza K.

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Academic Research Contributor in Health Sector (Volunteer)

Berlin
Hamza K.

Last position:

Academic Research Contributor in Health Sector (Volunteer) at n/a

  • Acted as technical consultant to optimize multi-layer ensemble models combining ResNet, CNN-BiGRU-Attention, and XGBoost.
  • Guided implementation of a Logistic Regression meta-learner to solve class imbalance problems, achieving 92.86% accuracy and 0.9644 AUC on PTB-XL and Chapman-Shaoxing datasets.
Verified expert

Syed A.

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Senior Software Engineer

Berlin
Syed A.

Last position:

Senior Software Engineer at Giant Eagle

  • Designed and developed AI-powered document processing solutions using Python, OCR, NLP, and Large Language Models (LLMs) to automate extraction, validation, and classification of financial documents, reducing processing time by 75%.
  • Built intelligent multi-stage workflow automation pipelines integrating AI services, machine learning models, and enterprise systems to streamline financial operations and improve data quality.
  • Developed reusable AI-driven transformation frameworks capable of processing structured and unstructured document formats (XML, CSV, JSON, TXT, DAT) and normalizing them into unified business schemas.
  • Designed and developed Python-based REST APIs and backend services supporting enterprise finance applications and high-volume data processing workloads.
  • Built scalable data synchronization pipelines between Oracle CFIN and SQL databases, incorporating machine learning models for cash-flow forecasting and AP/AR anomaly detection.
  • Architected and deployed Apache Airflow workflows to orchestrate AI-powered data pipelines, automating end-to-end processing from document ingestion through financial system integration.
  • Led the migration of critical enterprise integrations from MuleSoft to Python-based services, improving maintainability, performance, and operational flexibility while preserving complete data integrity.
  • Managed the full API lifecycle including solution design, implementation, documentation, deployment, monitoring, and production support for mission-critical financial systems.
  • Collaborated directly with finance stakeholders to identify business challenges, define solution requirements, and deliver measurable operational improvements through automation and AI-driven workflows.
  • Worked closely with cross-functional engineering and business teams to rapidly iterate on features, improve processes, and drive successful adoption of AI-enabled solutions.
  • Provided technical leadership through architecture reviews, technology decisions, code reviews, and engineering best practices across integration and automation initiatives.
  • Mentored developers, established coding standards, and contributed to improving software quality, maintainability, and delivery effectiveness across projects.
  • Provided production support during critical month-end and quarter-close financial processes, performing root-cause analysis and implementing rapid fixes to ensure system reliability and data accuracy.
Verified expert

Krishna M.

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Associate Product Manager

Berlin
Krishna M.

Last position:

Associate Product Manager at Carelon Global Healthcare LLP

  • Defined and executed product vision & strategy, collaborating with UX, architecture, and engineering teams, resulting in a 30% improvement in user satisfaction across key product touchpoints.
  • Owned end-to-end product lifecycle management, overseeing the launch of 5 major product updates, improving product efficiency and feature adoption by 25%.
  • Defined and structured epics, features, and user stories; validated and ensured 100% of completed stories met definition of ‘Done' before release.
  • Led backlog grooming, prioritization (WSJF, MoSCoW), and sprint planning, ensuring 95% on-time delivery of features in quarterly release cycles.
  • Worked with technologies: API, Angular, Node, ReactNative (Mobile), SQL, Kafka, AWS cloud with ES (Elastic search) with JSON file indexes.
  • Used Confluence and Jira for maintaining product details and product backlogs for 10 years.
  • Used Figma, Sketch, Miro for 4 years.
  • Directed cross-functional teams, coordinating with developers, designers, and business units, driving a 40% reduction in time-to-market for critical features.
  • Spearheaded product release demos, UAT, and go-to-market (GTM) strategies, leading to a 15% increase in user adoption within the first quarter of launch.
  • Optimized member experience on Anthem's digital health platform, resulting in a 20% increase in active user engagement and a 10% boost in member retention.
Verified expert

Santhosh K.

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Freelance Software Engineer

Berlin
Santhosh K.

Last position:

Freelance Software Engineer at Zalando SE

  • Drive migration of enterprise authorization platform from Styra DAS to open-source OPA via Skipper (Zalando's Golang-based ingress proxy) integration
  • Optimise k8s resources and integrate native Prometheus metrics with OPA
  • Migrate from internal monitoring solution to Prometheus CRs + Dash0

Tech Stack: Java/Kotlin, Golang, Python, Spring Boot, AWS, Kubernetes, Docker, OpenTofu, Prometheus, Grafana

Verified expert

Majid M.

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Senior Technical Product Manager - Platform & Automation

Berlin
Majid M.

Last position:

Senior Technical Product Manager - Platform & Automation at U.S. Legal Tech Platform

  • Owned product delivery for document automation and workflow platform used across multiple legal jurisdictions
  • Led integration across 6+ systems using API-based data exchange and structured data mapping
  • Partnered with engineering on data models, document generation workflows, and system orchestration
  • Evaluated LLM-assisted document automation opportunities to reduce manual drafting
  • Built functional prototypes to validate workflow and product concepts
  • ~2x increase in case processing throughput
  • Enabled multi-state rollout of platform capabilities
  • Reduced manual document generation and operational bottlenecks by 80%
Verified expert

Matthias O.

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Freelance work

Berlin
Matthias O.

Last position:

Freelance work at Etengo (für Syna AG)

  • Consulting in the SAP EAM module as part of the migration to EON's S/4 HANA oneERP system

  • Review and cost estimation of customer-specific developments (e.g. cockpit for EAM orders, document flow display)

  • Preparation of EAM classification data for technical objects (functional locations, equipment) for migration to new classes

Verified expert

Sunish B.

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Technical Program Manager . Engineering Delivery & AI Systems

Teltow
Sunish B.

Last position:

AtlasMind - Production AI assistant for Jira at Mercedes Benz Innovation Labs Gmbh

  • Converts natural language into JQL using RAG and pgvector. Returns structured JSON with a query, chart spec, and plain-text answer. A two-stage router answers general questions without touching the JQL pipeline at all.
  • Interchangeable LLM backends: Ollama, vLLM, Groq, Anthropic Claude, AWS Bedrock - switchable at runtime, no code changes. Self-healing JQL: on Jira validation failure, feeds error back to LLM, retries up to 4 times. OCI Vault for secrets. Deployed on Oracle Cloud A1 with GPU inference over Tailscale private network. Open source.
Verified expert

Mathias V.

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Senior Android Developer / Freelancer

Berlin
Mathias V.

Last position:

Fullstack AI Engineer at Ammodia.com

Developed a custom Kotlin Multiplatform app with a Spring backend and AI features.

Verified expert

Vito B.

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AI Architect | LLM & Agentic AI for Manufacturing, MedTech, FinTech, SaaS, IoT

Berlin
Vito B.

Last position:

AI Architect & Engineer (Founder) at Arcate

  • Impact: Arcate turns scattered customer signals into ranked product decisions for B2B product teams. Every initiative is prioritized by revenue at risk. Every decision is traceable from customer quote to board slide. Built solo, deployed in production. Model validated at Kendall's tau = 0.924 vs. senior PM judgment across 60 simulation runs.

  • Skills: Artificial Intelligence, AI Agent, Large Language Model (LLM), RAG, Model Context Protocol (MCP), Agentic Workflows, Supabase, TypeScript, Deno, PHP, Stripe, PostgreSQL, Product Strategy, Positioning, GTM

  • Capabilities:

  • Signal Ingestion: Slack, Intercom, Gong, Salesforce, HubSpot. Signals classified by business severity to prioritize revenue-risk decisions.

  • Revenue Scoring: Fermi Leverage model. Initiatives ranked by customer ARR at risk, signal strength, and multi-account confirmation.

  • Roadmap Intelligence: Every bet traceable from raw customer signal to scored, board-ready decision.

  • Built:

  • MCP Server (v0.10.0): 12 tools, JSON-RPC 2.0, Supabase Edge Functions, SHA-256 API key authentication.

  • Scoring engine: Log-scaled ARR weighting, sqrt-dampened signal strength, multi-account signal confirmation.

  • Agentic Workflows: 18 automated pipelines covering release, provisioning, design QA, guard QA, and signal ingestion via Slack agents.

  • AI Skills: 7 codified skills including CEO Prioritizer, Design System Enforcer, MCP QA, Simulation Runner.

  • Automated QA: Browser-based screenshot validation of every screen against design tokens on every build.

  • Full SaaS: Auth, billing, media pipeline, design system. Deployed solo in production.

  • Stack: Supabase (Auth, DB, Edge Functions, Realtime), Stripe, Cloudinary, PHP, TypeScript, Deno

Verified expert

Mohsin H.

View profile

Software Development Lead

Berlin
Mohsin H.

Last position:

BBM GenAI MiDAS program coordinator for Bosch eBike at Robert Bosch GmbH

The MiDAS program aims to integrate Generative AI across the entire BBM organization. My role is to enable the eBike division to adopt and leverage Generative AI by collaborating closely with the MiDAS team in India.

Management:

  • Enable the eBike division to adopt GenAI through tailored solutions.
  • Collaborate with the MiDAS team in India to design solutions for Generative AI use cases specific to the eBike division.
  • Coordinate with the eBike teams to integrate GenAI systems, tools, plugins, and services provided by the MiDAS team.
  • Plan roadmaps with eBike and MiDAS India team Product Managers for the delivery and integration of Generative AI solutions.

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)

JSON experts in Berlin have 17 years of professional experience on average. It is 2 years less than in Germany, where the average stands at 19 years.

Position duration

2.2 years (Germany: 5.2 years)

JSON experts in Berlin stay in a single position for 2.2 years on average. It is 3 years less than in Germany, where the average stands at 5.2 years.

Positions per freelancer

12 (Germany: 14)

JSON experts in Berlin have completed 12 positions on average over the course of their careers. It is 2 fewer than in Germany, where the average stands at 14.

Top business areas

Information Technology, Product Development, Project Management

JSON experts in Berlin have gathered most of their hands-on project experience in Information Technology, Product Development, and Project Management.

Top industries

Information Technology, Banking and Finance, Professional Services

JSON experts in Berlin are most in demand in Information Technology, Banking and Finance, and Professional Services.

Certification focus areas

Information Technology, Product Development, Project Management

JSON experts in Berlin earn their certifications most often in Information Technology, Product Development, and Project Management.

Bachelor's degree or higher

95% (Germany: 89%)

95% of JSON experts in Berlin hold at least a Bachelor's degree. It is 6% higher than in Germany, where the rate stands at 89%.

Master's degree or higher

63% (Germany: 56%)

63% of JSON experts in Berlin hold at least a Master's degree. It is 7% higher than in Germany, where the rate stands at 56%.

Doctorate

13% (Germany: 10%)

13% of JSON experts in Berlin have a doctorate (PhD). It is 3% higher than in Germany, where the rate stands at 10%.

Certifications per freelancer

1 (Germany: 2)

JSON experts in Berlin hold 1 professional certification on average. It is 1 fewer than in Germany, where the average stands at 2.

Most common languages

German, English, Spanish

JSON experts in Berlin most often speak German, English, and Spanish.

Speak two or more languages

96% (Germany: 98%)

96% of JSON experts in Berlin speak two or more languages. It is 2% lower than in Germany, where the rate stands at 98%.

Based on our profile pool as of 29 Oct 2026.

Daily rate distribution

0% 25% 50% 75% 100%
4% of JSON experts in Berlin charge less than €400 per day.
53% of JSON experts in Berlin charge between €400 and €800 per day.
33% of JSON experts in Berlin charge between €800 and €1200 per day.
9% of JSON experts in Berlin charge €1200 or more per day.
<€400 €400-​800 €800-​1200 €1200+

The chart shows how the daily rates of experts in this technology in Berlin 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 Berlin using JSON

Rates are based on recent contracts and do not include FRATCH margin.

800
600
400
200
Rate comparison chart
Daily rate avg. 739 €
Germany avg. 757 €

The average daily rate is the mean of all daily rates from recent contracts of comparable freelancers on our platform.

800
600
400
200
Rate comparison chart
Median rate 720 €
Germany median 760 €

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 (98%)
  • Banking and Finance (40%)
  • Professional Services (40%)
  • Media and Entertainment (38%)
  • Manufacturing (35%)
  • Retail (33%)
  • Automotive (31%)
  • Education (31%)

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 exchanging structured data. Its objects, arrays, strings, numbers, booleans and null values are easy for systems to parse and for people to inspect. Companies use it as a common contract between web applications, services, databases and external partners.

Where it runs

JSON is central to REST APIs, configuration files, event messages and browser-based applications. It carries customer records, product catalogues, payment states, analytics events and device data across many industries. In Berlin, specialists often support digital products, commerce systems, media services and connected business applications that depend on dependable data exchange.

Ecosystem skills

Strong JSON work includes more than producing valid syntax. Professionals work with HTTP, REST, GraphQL, OpenAPI, JSON Schema and authentication, while understanding how JavaScript, TypeScript, Python, Java, PHP or Go consume the data.

  • Define stable request and response contracts
  • Validate payloads with JSON Schema
  • Transform data between services and storage systems
  • Document endpoints with OpenAPI

When to hire

Companies bring in freelance expertise when an API needs a consistent contract, integrations fail because of ambiguous fields, or a legacy payload must evolve without breaking clients. Specialists can establish conventions, review existing interfaces and create migration plans. They also help teams prepare data for mobile apps, partner integrations, reporting pipelines or event-driven systems.

Quality signals

A capable professional distinguishes syntax validity from useful design. They choose clear names, predictable nesting and suitable data types; document optional and required fields; and handle missing, unknown or sensitive data deliberately. They test real payloads, consider backwards compatibility and explain trade-offs to product, security and delivery teams.

Collaboration in Berlin

JSON tasks may fit fully remote collaboration when the interfaces, sample payloads and acceptance criteria are documented. On-site work in Berlin can help when specialists must align several product teams, resolve ownership questions or work closely with local stakeholders. Clear communication in English, and German where needed, supports reviews and decisions across the project.

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Frequently asked questions

Not sure where to start with JSON? These answers cover the essentials.

JSON is mainly used to exchange structured data between applications, especially through web APIs. It also appears in configuration, event streaming, exports and data transformation workflows.

JSON is usually more compact and maps naturally to objects and arrays used in many programming languages. XML offers richer document features, such as attributes, namespaces and mixed content, so the better choice depends on the integration and validation requirements.

A strong JSON specialist should understand HTTP, REST, GraphQL, OpenAPI and JSON Schema. Knowledge of authentication, versioning, testing and at least one backend or frontend language is also important.

The right level depends on the task. A simple payload change may need focused integration experience, while designing contracts across many services requires a professional who understands versioning, validation, error handling and backwards compatibility.

Yes. JSON work is often well suited to remote collaboration when API documentation, sample payloads and review processes are available. For Berlin-based teams, occasional on-site sessions can help when several departments must agree on data ownership or interface design.

Review whether the JSON structures are consistent, documented and validated against realistic data. Ask the professional to explain naming, optional fields, error responses, security considerations and how changes can be introduced without disrupting existing consumers.

JSON Schema is not mandatory for every API, but it provides a precise way to describe and validate payloads. It becomes especially useful when several teams, services or external partners must share the same contract.

JSON describes data for exchange or representation; it does not replace a database's storage, indexing or transaction features. A service may read records from a relational or document database and serialize them as JSON for an API or application.

The average hourly rate of freelancers in Berlin, Germany who have used JSON in their recent projects is 92 €, which corresponds to a daily rate of about 739 € based on an 8-hour working day.

Of the freelancers in Berlin, Germany who have used JSON in their recent projects, 95% hold at least a Bachelor's degree, 63% hold at least a Master's degree, and 13% hold a doctorate.

On average, freelancers in Berlin, Germany who have used JSON in their recent projects have 17 years of professional experience, with a single engagement typically lasting around 2.2 years.

The most common languages among freelancers in Berlin, Germany who have used JSON in their recent projects are German (96%), English (96%), and Spanish (13%).

The most common industries among freelancers in Berlin, Germany who have used JSON in their recent projects are Information Technology (98%), Banking and Finance (40%), and Professional Services (40%).

The most common business areas among freelancers in Berlin, Germany who have used JSON in their recent projects are Information Technology (96%), Product Development (92%), and Project Management (54%).

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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