
Event Sourcing Experts in Germany
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Meet FRATCH Experts in Germany, who have recently used Event Sourcing
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
Aamir S.
Last position:
Founder at Self-Directed Project Work
- Building independent projects in the AI/developer tools space.
- Experimenting with product ideas, rapid prototyping, and go-to-market validation.
- Designing AI-native operating model—leveraging agentic pipelines, living context schemas, and rigorous eval harnesses to multiply individual contributor leverage and eliminate implementation bottlenecks.
Thomas H.
Last position:
Senior MLOps, DevOps Engineer at Trianel Energy
- Build and operate an end-to-end MLOps platform on Azure ML and Kubernetes (Kubeflow) for the automated deployment, monitoring, and scaling of forecasting models (including Temporal Fusion Transformer, Informer, Autoformer).
- Implement CI/CD pipelines in Azure DevOps for the full ML lifecycle – from resource provisioning (Terraform), data transformation (Hugging Face Datasets, Pandas, PyTorch, CUDA cluster) through training and evaluation to model registry and endpoint deployment.
- Integrate MLflow for experiment tracking, model versioning, performance monitoring, and automated registration in the Azure Model Registry.
- Develop and containerize PyTorch training jobs (Azure Notebook, Jupyter Notebooks) for price and time series forecasting (PFC models) with automatic rollout via Azure ML Endpoints and REST/gRPC interfaces, Docker containerization, secured with OAuth 2.0.
- Set up monitoring and alerting mechanisms (Prometheus, MLflow Metrics), log centralization, and cost monitoring.
- Automate infrastructure provisioning and model deployment using Terraform, Helm, and Azure CLI; connect to existing market data systems and event pipelines.
- Migrate existing workloads and databases (IONOS → Azure, MongoDB) with integration into central MLOps workflows and internal networks.
- Extend the platform with LLM-based tools (LangChain, LangServe) to integrate GPT-based analysis modules into existing Spring Boot services for market anomaly detection and automated reports.
- Analyze and architect a software solution to process large volumes of data efficiently (>3000 messages/sec.) (market data store).
- Spring Boot / Java 21 container development with RabbitMQ for distributing stock market data via MongoDB (Kubernetes) with fast storage of data in Redis RMaps, deduplication, forwarding messages to Read Model queues, and building Read Models for UI display in MongoDB.
- Integration of RESTHeart to create a REST API for MongoDB.
- Build an Angular frontend to simplify data queries and master data maintenance.
- Agentic coding with remote and local LLMs (Claude Sonnet, Ollama Qwen) and MCP servers.
- Develop Python scripts for transforming and cleaning incoming stock market data (Pandas, scikit-learn).
Thorsten B.
Last position:
Senior Backend Engineer at VTG Rail Europe
traigo is VTG's digital rail logistics and fleet management platform. It processes large volumes of telemetry, mileage, geofence, sensor and wagon-movement events in near real time and provides operational services for rail logistics customers across Europe.
As part of Team Customer Selfcare, I worked on the design, implementation, optimisation and operation of large-scale backend services and event-driven processing pipelines — covering both feature development and operational ownership of business-critical production systems. I also regularly acted as first responder for production incidents, data inconsistencies and performance investigations across multiple distributed services.
- Design and implementation of event-driven backend services.
- Migration and replacement of legacy processing pipelines.
- Development of replay / rebuild mechanisms for large event datasets.
- High-throughput asynchronous event processing on SNS / SQS.
- Database and query optimisation for PostgreSQL and DynamoDB.
- Design of scalable read / write models and aggregation pipelines.
- Production troubleshooting and operational support.
- Performance tuning and infrastructure scaling.
- Design and stabilisation of integration and system tests.
- Technical concepts, architecture documentation, and cross-team collaboration.
- Support the further development of existing GitLab CI/CD pipelines
Geofence & Wagon Stay Processing
- Algorithm to detect vehicles within geofences (entry, exit, dwell time).
- Event sourcing with guaranteed chronological order within the affected time window.
- Refactored geofence event and wagon-stay processing logic for performance.
- Resolved race conditions and event-ordering problems in distributed services; server-side filtering, aggregation and optimised query pipelines.
- Repair and replay tooling for corrupted or inconsistent movement data.
Fleet Metadata & Mileage
- Modernised the service; migrated storage from DynamoDB to PostgreSQL to improve traceability and accelerate new features.
- Scalable mileage aggregation and replay mechanisms.
- Read / write models and optimised queries for high-volume mileage calculations.
Sensor & Telematics Integration
- Integrated telemetry and sensor processing pipelines.
- Snapshot and state-calculation logic for sensor systems.
- APIs and persistence models for wagon sensor data; data-quality improvements.
- Further development of a service using gRPC for intra-service communication.
Movement Segment Processing & Routing
- Migrated services to new movement-segment event streams.
- Built replay and rebuild tooling for segment correction.
- Optimised throughput and reliability for high-volume event processing.
Condition Monitoring & Wagon Analytics
- APIs and backend services for wagon condition monitoring.
- Brake-wear prediction processing and wagon analytics functionality.
- PostgreSQL views and optimised query models for operational dashboards.
Operational Reliability - First Responder
- Investigated production incidents and distributed-system failures; DLQ analysis, replay and operational recovery.
- Tuned database performance and AWS infrastructure under production load.
- Improved observability, monitoring and operational tooling.
- Supported rollout strategies, monitoring and post-deployment stabilisation.
Waldemar B.
Last position:
Software-Architekt Produktdaten-Management Tool at Ferchau Contract GmbH
- Definition of the software architecture
- Design and development of modules
- Supporting internal employees in the learning and onboarding process
- Tools: SAP CAP / CDS, Java 21, SAP Hana, SAP Business Technology Platform (BTP)
Marc H.
Last position:
Senior Architect, Coach and Developer
Fixing issues in the program logic
Covering the changes with unit tests
Analyzing and documenting the data structure of the various applications
Analyzing and documenting the parameters for configuring the applications
Analyzing and documenting the measures required to ensure the operation of the applications
Analyzing and designing the separation of the individual database structures
Analyzing and estimating the effort for planned extensions
Analyzing, maintaining and documenting a heterogeneous legacy system landscape for a print media service provider
Technology: C#, VB.NET, C, Python, Microsoft SQL Server, Visual Studio 2010, JetBrains Rider, Visual Studio Code, arc42, Draw.io, Jira, GitLab
Rolf W.
Last position:
Agile Consultant at Lead.ai
- Introduction of Agile-CCPM in an IT project agency with a focus on PHP-based content management systems.
- Preparation and facilitation of workshops to establish a cross-agency multi-project management system.
- Coordination and support of the agency partners.
- Coaching of the methodological framework.
- Collection, evaluation, and use of organizational metrics to plan next steps.
- Environment: OKR, CCPM, Agile Coaching, Agile Planning, Agile Metrics, Workshops, Facilitation, Change Management, JIRA, Zoom, Slack, Miro.
Nikunjkumar P.
Last position:
Senior Java Backend Developer at Questax Professionals GmbH
- Provide the Price Listing Service team with prices for all cars and vans in different markets
- Adapt market-specific requirements such as taxes, government subsidies, campaigns
- Import and synchronize new prices for all new and existing cars and store them in the Redis datastore
- Support our product and on-call duty
- Daily business, development of new features, bug fixing
- Pair programming, code review, mob programming
- Develop POCs for new ideas
- Maintain and extend the backend
- DevOps tasks
- Run Kubernetes updates
- Adjust and further develop Kubernetes resources
- Develop and adapt Helm charts
- Adapt and update ArgoCD
- Maintain, adapt, and improve CI/CD
Robin S.
Last position:
Senior Cloud & Backend Engineer at Media-Saturn-Holding GmbH
- Implementing applications with Kotlin and Ktor as microservices
- Using MongoDB in the MongoDB Atlas cloud
- Asynchronous communication of services via Google Pub/Sub
- Using Kotest and MockK for unit tests
- Developing an administration frontend with TypeScript, React and Express.js
- Provisioning environments in GCP using Terraform
- Implementing CI/CD processes with GitHub Actions
- Operating scalable production and test environments in GCP with Kubernetes, Helm and Flux CD
- Monitoring environments with Prometheus and Grafana
- Providing BI data in the Google BigQuery data warehouse
Jan H.
Last position:
Technical Co-Founder at Telemarie UG
- Technical leadership & SW architecture: Conducted trade-off analyses for technology stacks and led the design and implementation of the software architecture, including mobile and backend solutions. Facilitated Event Storming workshops for DDD and SW architecture.
- Strategic direction & organizational development: Played a key role in defining the strategic direction of the product and organization, exploring new forms such as ownership responsibility.
- Lean Startup & Agile development: Introduced Lean and Agile principles, implemented Lean prototypes, and ensured compliance with Lean Startup processes, iteratively moving from Product/Solution-Fit to Product/Market-Fit.
- Team building & collaboration: Facilitated workshops, retrospectives, and futurespectives to collaboratively develop tactics and strategies.
- Technologies: Flutter, JS/TS, React, Google Cloud, Firebase, Android, iOS.
- Organizational methods: Lean startup, lean canvas, lean agile, event storming, retrospectives.
Hüseyin K.
Last position:
Senior Full-Stack Engineer at DVAG
Architecture and implementation of a fully digitalized closing flow for managing securities contracts within the DVAG infrastructure. The platform aims for maximum user-friendliness, modular extensibility and compliant handling of sensitive data.
Implementation of a reactive UI structure with a focus on user guidance & accessibility.
Dynamic control of form and closing processes including validation logic.
Reactive state management via SignalStore (signals + selective effects).
UX optimization through adaptive components and Playwright-based UI tests.
Backend modularization to connect existing sales and contract logic.
API stability and DTO design according to Clean Architecture principles.
Collaboration with domain teams to define technical contracts and service boundaries.
Management with GitHub.
Unit tests with Jest, E2E tests with Playwright.
Code reviews, CI-integrated test execution, iterative refactorings.
Ensuring high coverage and UI stability in the closing flow.
Technologies: Angular 18, RxJS, SignalStore, HTML5, SCSS, Spring Boot, Kotlin, REST, OAuth2, Jest, Playwright, Clean Architecture.
Enis S.
Last position:
Software Developer at 50Hertz Transmission GmbH
- Participated in the gradual modernization of components into cloud-native 12-factor applications.
- Worked closely with the business operations team to eliminate manual processes and resolve several performance bottlenecks.
- Designed and implemented a CI/CD pipeline to increase developer productivity, enforce quality and security checks, and automate product delivery.
- Migrated several components into the OpenShift Kubernetes cluster.
- Built a monitoring stack from scratch with Prometheus and Grafana to monitor services running in OpenShift.
- Developed dashboards in both Grafana and Splunk for operational transparency.
- Implemented an OIDC/OAuth2-based single sign-on (SSO) solution with Keycloak to secure multiple applications.
- Technologies: Java, Spring, Quarkus, Kafka, MySQL, Cassandra, Redis, Spring Data, Hibernate, Docker, Kubernetes, OpenShift, Keycloak, OIDC, OAuth2, Helm, Prometheus, Grafana, Splunk, Spark.
Ioan D.
Last position:
Senior Software Developer at ING
- Tribe Home, Product Area 4 - Customer in Life, Squad Cybertron.
- Analysis, design, development, and testing of new requirements for Optimmo, construction financing software.
- Analysis, design, development, and testing of the JEE application MWS kredit-baufi.
- Analysis, design, development, and testing of the Wicket Optimmo application.
- Analysis, design, development, and testing of kredit-baufi batch programs.
- Migration of kredit-baufi batches to RHEL9.
- CiL SCS Consumer Pacts with Finagle.
- CiL ScS Touch Point Architecture Integration.
- Team size: 10.
- Tools / Frameworks: OpenJDK Java 17, Kotlin 1.6.0, Azure, Jenkins, Stash, JEE, Gitlab, JIRA, Confluence, git, Spring 6.0, Sping Cloud, Spring Data, Hibernate, JPA, JMS, Kafka, Oracle, PL/SQL, Red Hat Enterprise Linux (RHEL), Maven, REST, JBoss, Intellij IDEA, Wicket 9 and 10, Istio.
Jörg N.
Last position:
Senior Software Architect at Nieveler IT Consulting
- Redesign of the “Hessian Platform for Migration and Refugees”
- Technologies: C#, .NET 8.0, ASP.NET WebAPI, Blazor
- Architecture principles: Domain Driven Design, Mediator Pattern, Outbox Pattern, IOSP, Clean Code
- Methodologies: SCRUM, coaching, team lead
Fady K.
Last position:
Senior Software Developer / Tech Lead at Specific Objects Technologies GmbH
- Project 1: Multi-Tenant SaaS Platform: Data Integration & Pricing Management
- Objective: New development of ELT pipeline (replacement for Java 6 legacy), integration of heterogeneous source systems (CSV, Excel, Email, external DBs), event-sourcing for complete auditability, multi-tenant architecture for tenant-capable data processing
- Challenge: Processing millions of records daily, audit compliance, data isolation between different tenants
- Solution: Stakeholder workshops for requirements analysis, event-driven architecture with Axon Framework and Apache Kafka, AWS services (EC2, S3, Lambda, SQS, API Gateway) for cloud integration, PostgreSQL with tenant-specific schemas for multi-tenant data isolation, REST API design with Spring Boot for external system integrations, comprehensive testing strategy (JUnit, Spring Test, Postman, PACT, ArchUnit)
- Results: ELT performance improved from 30+ min to 1-5 min; 2-3 hours daily saved through workflow automation; 10-20 hours/week saved through event-sourcing auditability; 100% audit compliance; secure multi-tenant data isolation for 10+ tenants
- Project 2: Multi-tenant CRM System Modernization
- Objective: Migration of CRM system (20+ years PHP/MySQL) to Java microservices, Domain-Driven Design implementation, establishment of Test-Driven Development, multi-tenant-capable SaaS architecture for multiple customer tenants
- Challenge: Remodeling complex business logic, no existing test culture, scalable tenant management with data isolation
- Solution: Comprehensive testing strategy (JUnit, Spring Test, Postman, PACT, ArchUnit), multi-tenant architecture with tenant-specific databases, REST API design with Spring Boot for cross-tenant integration, Kubernetes and Docker for container orchestration
- Results: 2× performance improvement; deployment time reduced from 40+ min to 5-7 min; migration without production outages; scalable multi-tenant solution for 15+ customer tenants
- Technologies: Java, Spring Boot 3.x, Angular, Apache Kafka, AWS (EC2, S3, Lambda, SQS, API Gateway), PostgreSQL, Axon Framework, Kubernetes, Docker, GitLab CI, REST API
Discover over 15,000 top freelancers
Statistics of experts using Event Sourcing
Aggregated from the professional profiles of matched freelancers.
Experience
20 years

Position duration
2.4 years

Positions per freelancer
13

Top business areas
Information Technology, Product Development, Project Management

Top industries
Information Technology, Banking and Finance, Education

Certification focus areas
Information Technology, Product Development, Project Management
Bachelor's degree or higher
86%
Master's degree or higher
50%

Certifications per freelancer
3

Most common languages
English, German, French

Speak two or more languages
100%
Based on our profile pool as of 29 Oct 2026.
Daily rate distribution
The chart shows how the daily rates of experts in this technology in Germany 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 Germany using Event Sourcing
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 29 Oct 2026. Actual rates may vary depending on seniority level, experience, skill specialization, project complexity, and engagement length.
Event Sourcing 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%)
- Banking and Finance (53%)
- Education (43%)
- Retail (43%)
- Automotive (37%)
- Media and Entertainment (37%)
- Transportation (33%)
- Manufacturing (33%)
Please note that freelancers can work across multiple industries, so percentages overlap.
About the technology
Core principle
Event Sourcing stores changes to business data as an ordered stream of immutable events instead of keeping only the latest state. An application rebuilds the current state by replaying those events. This preserves a detailed history of decisions and makes past states auditable, while requiring careful event design and versioning.
What it builds
Event Sourcing suits systems where business history matters and state changes drive further actions. It appears in financial workflows, order management, inventory, insurance claims, billing, identity services and other distributed domains. Event streams can support audit trails, projections, reporting and asynchronous integrations.
- Model domain events and aggregate boundaries
- Rebuild state through event replay
- Create read models for different user needs
- Publish reliable events to connected services
Ecosystem and tooling
Strong professionals work across the architecture around the event store, not just the persistence layer. Common choices include Axon Framework, EventStoreDB, Kafka, PostgreSQL and cloud messaging services. They also use CQRS, domain-driven design, schema registries, snapshotting and observability tools where the system requires them.
When expertise matters
Companies bring in freelance specialists when a new service needs an auditable history, when a conventional database model blocks scalability, or when a distributed system needs dependable integration. Expertise is also valuable during a migration from CRUD-based services, a redesign of aggregates or the recovery of inconsistent projections.
- Business rules are difficult to trace through current tables
- Teams need reproducible historical states
- Multiple services must react to the same domain change
- Read and write workloads need separate models
Delivery and collaboration
An Event Sourcing project needs clear event contracts, ownership rules and operational controls from the start. Freelance experts define replay and migration strategies, handle idempotency, manage eventual consistency and test failure scenarios. In Germany, remote collaboration is common, while language expectations and on-site workshops should be agreed before delivery begins.
Quality signals
A strong professional explains why Event Sourcing fits the domain instead of treating it as a default database pattern. Look for experience with event evolution, aggregate design, projection rebuilding, observability and data protection constraints. Good specialists document trade-offs, keep events meaningful to the business and make recovery procedures practical for the operating team.
Frequently asked questions
Quick answers to the questions that come up most around Event Sourcing.
Event Sourcing records each meaningful change as an event and derives current state from that history. Companies use it for auditable workflows, event-driven integrations, financial records, order lifecycles and domains where past decisions must remain available.
Event Sourcing keeps a durable sequence of state changes, while a CRUD model usually stores the latest values in place. The event-based approach improves traceability and replay, but it adds responsibility for event schemas, projections, eventual consistency and operational recovery.
Event Sourcing and CQRS are related but separate patterns. Event Sourcing defines how changes are persisted; CQRS separates command handling from queries. They can be used together, but either can be applied without the other.
A capable Event Sourcing specialist should understand domain-driven design, aggregate boundaries, CQRS and distributed systems. Practical experience with Kafka, Axon Framework, EventStoreDB, schema evolution, observability and automated testing is also valuable.
The right level depends on the domain risk and the scope of the event model. A small service may need focused event design and projection skills, while a core platform requires proven judgment around migrations, replay, consistency, failure handling and long-term event evolution.
Event Sourcing work is often suitable for remote collaboration because event contracts, architecture decisions and test results can be reviewed asynchronously. On-site workshops may still help when domain experts need to align on business events, ownership and terminology in a German organisation.
Ask the specialist to explain a real event model, including aggregate boundaries, versioning, replay and projection recovery. Strong answers connect technical choices to business rules and show how the design handles duplicate messages, failed consumers and changing requirements.
Event Sourcing may be unsuitable when only the current state matters, business rules are simple, or the team cannot support event versioning and operational monitoring. A professional should be willing to recommend a conventional persistence model when its lower complexity better serves the system.
The average hourly rate of freelancers in Germany who have used Event Sourcing in their recent projects is 97 €, which corresponds to a daily rate of about 773 € based on an 8-hour working day.
Of the freelancers in Germany who have used Event Sourcing in their recent projects, 86% hold at least a Bachelor's degree and 50% hold at least a Master's degree.
On average, freelancers in Germany who have used Event Sourcing in their recent projects have 20 years of professional experience, with a single engagement typically lasting around 2.4 years.
The most common languages among freelancers in Germany who have used Event Sourcing in their recent projects are English (100%), German (93%), and French (17%).
The most common industries among freelancers in Germany who have used Event Sourcing in their recent projects are Information Technology (100%), Banking and Finance (53%), and Education (43%).
The most common business areas among freelancers in Germany who have used Event Sourcing in their recent projects are Information Technology (100%), Product Development (100%), and Project Management (57%).
Main locations of FRATCH Experts, who have recently used Event Sourcing
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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