ASP.NET Web API Experts in Germany
to shape reliable services, matched in minutes with vetted and available freelancersHire experts who build secure REST APIs, connect .NET services to databases and cloud infrastructure, and modernize ASP.NET Web API 2 applications. FRATCH finds a precise match quickly from vetted, available freelancers.
Meet FRATCH Experts in Germany, who have recently used ASP.NET Web API
Matthias S.
Last position:
Software Developer and Consultant at CLADE GmbH
- Analysis of the existing CAN communication between microcontrollers
- Analysis of the sensors used and the measured values collected
- Planning the CAN messages for transmitting the measured values
- Iterative adjustment of the microcontroller code to the new CAN messages
- Cross-compilation from x64 to arm64
Saqib J.
Last position:
AI Developer / AI Engineer (Lead) at KOM4TEC GmbH
- Conceptual design and implementation of modular AI assistants for sales and business processes in the Microsoft ecosystem (Agentic AI, Copilot extensions)
- Frontend architecture and development with React + TypeScript for embedded chat and assistant surfaces (streaming UI, hooks, React Query, OpenAPI clients)
- Enterprise-level agent development: reusable skill/agent library, MCP server, review and compliance gates
- LLM integration into the user experience: Anthropic (Claude), OpenAI, tool use, RAG pipelines, prompt engineering, guardrails
- Architecture and code review consulting as well as mentoring in the AI development team
- Integration with Microsoft Graph, Power Platform, and Azure services
- Technologies: React, TypeScript, Anthropic Claude, OpenAI, MCP, RAG, Microsoft Graph, Power Platform, Azure
Manuel K.
Last position:
.NET Developer, SAP Business One Consultant at Own Projects
- DTO class generator: In-house development of a tool for the automatic generation of classes, functions, and methods for use in .NET Core projects based on SAP Business One Service Layer metadata
- E-invoice import add-on: Development of a SAP Business One add-on / coresuite module for the automated import of ZUGFeRD e-invoices as incoming invoices – with configurable mapping to flexibly control the import logic across four mapping types (DIRECT, SQL, FIXED, EXPR). The add-on is available as a licensed product for SAP Business One customers.
Stack: SAP Business One, SAP Business One Service Layer, coresuite Country Package, C#
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 L.
Last position:
Senior Security Analyst
- Analysis and remediation of security vulnerabilities in a risk assessment system for energy trading
- System analysis
- Threat modeling
- Decision-making on vulnerability mitigation strategies
- Implementation of vulnerability detection mechanisms
- Security scans
- DevSecOps practices
- Technical environment: Visual Studio Code, JetBrains Suite, MS Threat Modeling Tool, DevSecOps, Git, AWS, DynamoDB, SQL Server, Endur, Snowflake, Orca
- Languages: C#, JavaScript, TypeScript, Python, PowerShell, Bash, Terraform, SQL
Rizwan B.
Last position:
Software Developer/Database/Devops at Sutor Bank
Project:
- Migration of existing VB6 applications to C# (Web API, web app)
- Report development and risk management systems (C#, API interfaces, databases)
- Document archive (API interfaces, databases)
Team size: 9 people
- Reports for Risk and Credit Management Development and maintenance of report structures to support risk and credit decisions, including data modeling, validation, and automated delivery for business departments.
- Migration and maintenance of a legacy system to the latest version of .NET for the asset management system Planning and execution of the modernization of an existing asset management system, including code refactoring, performance optimization, test automation, and sustainable maintenance after migration.
- Replacement of the COM-based archive connection with a REST API Redevelopment of the connection of the document archive (HYPARCHIV) to a REST API based on OpenAPI/Swagger, including archiving with index and stamp fields as well as PDF export into the customer portal.
- Redesign of payment receipt processing Replacement of an existing Oracle PL/SQL process with a new implementation in C# based on a business concept, including business alignment, data modeling, and test coverage.
- Design and implementation of tests, creation of deployment pipelines, and documentation
- Further development and implementation of change requests.
- Regular code reviews within the team as well as optimization of application scalability and stability
Technologies: C#, .NET 10, ASP.NET, Unit of Work, IoC, Three-Tier Architecture, Entity Framework Core, DB First, Web API, Swagger, OpenAPI, Python, Oracle, HYPARCHIV, Azure, PowerBI, DevOps, AKS (Azure Kubernetes Service), GIT, xUnit, NSubstitute, TypeScript, Vue.js, Pinia,
Methods: agile development using Scrum
Oliver F.
Last position:
Modernization of a multi-company backend system at Energy utility company
Enhancement and modernization of a mature Aspire backend application in the environment of a utility company, focusing on new business requirements, testing, legacy code cleanup, and stable backend delivery.
Core contributions & results Implemented new business requirements in the context of customer orders, subcontractors, and cross-company backend processes, and ensured consistent workflows in a distributed system landscape. Modernized existing backend components step by step and reduced technical debt through targeted legacy code cleanup, refactoring, and structured code reviews. Improved the testability of business-critical services by expanding automated tests with xUnit, AutoFixture, and clearer validation structures. Supported the further development of workflow automations and integration processes via microservices, messaging, and API-based communication. Took over source code from external firms, systematically checked code quality, and derived technical improvements for maintainability, stability, and integration. Worked in agile development processes with Jira, Confluence, and Azure DevOps and supported cross-team alignment on architecture, quality, and implementation. Technical metrics Technologies & methods C#, .NET, ASP.NET, ASP.NET Core, Aspire, Docker, RabbitMQ, gRPC, REST API, Swagger, Microservices, NServiceBus, AutoMapper, Autofac, xUnit, AutoFixture, FluentValidation, Entity Framework Core, MediatR, Redis, Consul, Serilog, SonarQube, Azure DevOps, Azure Monitor, GitLab, Google Protocol Buffers, IronPDF, Mailjet, Jira, Confluence, Miro, agile development, Scrum, code reviews, refactoring, legacy code cleanup, workflow automation, power grids
Andreas G.
Last position:
Senior Fullstack .NET (Core) & Angular Developer at IT Service Provider
- Supporting several agile teams in the new product development of an enterprise CRM and ERP application
- Web frontend development with Angular 17–21 (microfrontends, Domain-Driven Design, MDB-Bootstrap)
- Backend development with C# and .NET 7–10, MongoDB, MassTransit, RabbitMQ, Entity Framework Core, ElasticSearch (microservices, DDD)
- Technical feature design for assigned tasks
- Technical architecture design including forward-looking planning of AI-supported extension options
- Proof-of-concept implementation of AI-supported workflows with n8n and a locally hosted LLM (Ollama)
- Coordination with stakeholders and Product Owners, support with sprint planning
Result: Delivery of production-ready microservices and frontend modules in agile sprint cycles.
Environment: .NET 7–10 · Angular 17–21 · C# · TypeScript · OpenAPI · Microfrontends · DDD · Kubernetes · Docker · Helm · MS SQL Server · PostgreSQL · MongoDB · MassTransit · RabbitMQ · EF Core · ElasticSearch · Kibana · Azure DevOps · KeyCloak · n8n · Ollama
Moritz F.
Last position:
AWS Developer/DevOps Engineer (Energy Trading) at RWE Supply & Trading GmbH
- Further development and partial new development of a distributed cloud application for providing data in energy trading
- Independent implementation of the infrastructure (IaC)
- Creation of automated CI/CD pipelines, containers, REST APIs, and Lambdas
- Continuous cost and performance optimization
- Collaboration in an international Scrum team and with experts in energy trading
- Technologies: C#/ASP.NET Core; EF Core; PostgreSQL; Terraform/AWS CloudFormation; HTTP; REST/Web API; Swagger/OpenAPI; Azure DevOps; Rider; VS Code; git; Docker; AWS (S3, EC2, Fargate, Lambda, Step Functions, Secrets Manager, VPCs, ALB/NLB, RDS, Cloudwatch, AWS CLI, Amazon MQ); Redis; OAuth; OpenID Connect
- Languages: C#; TypeScript; HCL; Docker; Bash; PowerShell; YML; JSON
Gavrilo O.
Last position:
Head of Software Development at Davidsmeyer & Paul GmbH
- Strategic project development, realisation, and implementation with internal and/or external development team
- Multi stakeholder management
- Planning new projects, cost calculation, risk calculation
- AI project for the electrical components production
- Building management systems integrations (BACnet, Modbus, etc)
- Inhouse BACring system architecture and development (control system for fire protection and smoke extraction systems)
- Inhouse MES system architecture and development
- Project management
- Agile-SCRUM project development
- Solution architecture and processes analytics (UML)
- Business application development
- Jira project management
- Reporting and documentation
- Recruitment process for the IT staff
- Software architecture, project development, costs, risks
- Education IT staff (internal and external)
- Responsibility for 5 development/DevOps/QA teams
Michael S.
Last position:
Senior Software / Full-Stack Developer at DOUGLAS INFORMATIK & SERVICE GmbH
- data integration for SAP marketing applications Emarsys and SMC
- processing data from SAP applications for email delivery
- event-driven architecture with around 50 microservices for processing several million messages per day during high season
- development of a marketing campaign management tool (frontend Angular, backend C# ASP Web API)
- support for the Product Owner in communication with stakeholders and creation of epics, stories, and tasks
Hicham M.
Last position:
Freelance Software Developer at Buhl Data Service GmbH
- Backend development: .Net 8, C#, PostgreSQL, Entity Framework Core, REST Web APIs, Docker, Kubernetes, Kafka, Open API Swagger, Apache Airflow, Resharper, Git, Microservices, SOAP, gRPC, Hangfire, OAuth 2, GraphQL
- Interface development for document processing with SmartFix, Softexpansion and Natif.ai: C#, REST API, Resharper, Git
- Deployment: Azure DevOps YAML, Vanilla Helmchart, Rancher, Kubernetes Cluster, Linux Docker, Windows VM, Python
- Unit tests and integration tests
- Telemetry, Kibana, Grafana, Elastic Search
- Work in a Kanban team of 8 developers, 1 tester and one Product Owner
Tobias W.
Last position:
Lead Architect / Senior Developer at Deutsche Bahn / Systel GmbH
- Design and lead development of a reactive, highly scalable supervision module
- Created a highly available, distributed solution for real-time visualization of critical system states
- Optimized operational stability and responsiveness
- Technologies: architecture, C#, .NET, Kafka, microservices, AWS, Next.js, React
Dimitrij N.
Last position:
Logistics Designer / Network Designer at Deutsche Bahn Cargo
- Requirements analysis, design, and development of a product for freight logistics (dispatching, planning, timetable and network optimization)
- Documentation of technical focus areas and support with acceptance and integration testing
- DBMS-agnostic modeling and mathematical algorithms for optimization with solver integration (Gurobi, Cplex, Coin-OR)
- Implementation of service layer, automated testing, and integration with third-party systems
Holger K.
Last position:
Data Migration Sage 100 to Odoo at LRT Automotive
- SQL database development, design, documentation of procedures, functions, and triggers
- Migration of data from the Sage Line 100 database to Odoo
- DB design with MS SQL Server and SQL (T-SQL)
- Use of Power Query and Excel
Discover over 15,000 top freelancers
Statistics of experts using ASP.NET Web API
Aggregated from the professional profiles of matched freelancers.
Experience
22 years
Position duration
3.1 years
Positions per freelancer
14
Top business areas
Information Technology, Product Development, Quality Assurance
Top industries
Information Technology, Manufacturing, Banking and Finance
Certification focus areas
Information Technology, Product Development, Project Management
Bachelor's degree or higher
81%
Master's degree or higher
46%
Doctorate
3%
Certifications per freelancer
2
Most common languages
German, English, French
Speak two or more languages
98%
Based on our profile pool as of 19 Sep 2026.
Daily rate distribution
The chart shows how the daily rates of freelancers in this technology in 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 ASP.NET Web API
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.
ASP.NET Web API 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 (96%)
- Manufacturing (54%)
- Banking and Finance (46%)
- Healthcare (42%)
- Transportation (42%)
- Automotive (33%)
- Energy (33%)
- Professional Services (33%)
Please note that freelancers can work across multiple industries, so percentages overlap.
About the technology
What ASP.NET Web API does
ASP.NET Web API is a Microsoft framework for building HTTP services that expose application data and actions through APIs. It is widely used for REST endpoints that support web front ends, mobile apps, partner integrations and business systems. Modern projects often use ASP.NET Core Web API, while established systems may run on ASP.NET Web API 2.
Services and integrations
The technology handles routing, controllers, model binding, validation, serialization and HTTP responses. Experts use it to create clear service contracts and connect applications to SQL Server, Entity Framework Core, message brokers and external providers. OpenAPI and Swagger make endpoints easier to document, test and consume.
Ecosystem and delivery
Strong work in this stack covers C#, .NET, dependency injection, middleware, authentication and authorization. Depending on the system, professionals also work with JWT, OAuth 2.0, Azure, Docker, Kubernetes, automated testing and CI/CD pipelines. They understand how API design affects browsers, mobile clients and distributed services.
Typical project needs
- Create REST APIs for customer portals, mobile applications or internal tools
- Split legacy ASP.NET Web API 2 services into maintainable .NET components
- Add identity, permissions, validation, logging and error handling
- Document endpoints with OpenAPI and improve integration test coverage
- Connect APIs to databases, queues, cloud services and partner systems
Companies bring in freelance specialists when an API must launch quickly, support a new product or replace fragile integrations. In Germany, they may join a local team on site or collaborate remotely across product, security and operations functions. Clear technical English and, where needed, German communication help keep decisions moving.
When to hire expertise
Freelance expertise is useful when internal teams lack capacity for a migration, need a short-term API lead or face reliability and security issues in production. A specialist can review endpoint design, reduce coupling, define versioning rules and establish practical release processes. The right scope depends on the system’s age, integration risk and delivery goals.
What good professionals show
A strong professional explains trade-offs instead of treating every endpoint alike. They use consistent resource design, appropriate status codes, secure input handling, resilient database access and useful observability. Look for evidence of tested APIs, effective documentation, backward-compatible changes and collaboration with the teams that consume and operate the service.
Frequently asked questions
Everything clients usually want to know about ASP.NET Web API, in one place.
ASP.NET Web API is used to create HTTP services that expose data and business operations to web applications, mobile clients, internal tools and partner systems. It commonly supports REST APIs with JSON responses, authentication, validation and database access.
ASP.NET Web API usually refers to the older .NET Framework-based stack, including ASP.NET Web API 2. ASP.NET Core Web API is the newer, cross-platform approach with a unified .NET runtime, built-in dependency injection and a different hosting model, so migration requires careful review of middleware, libraries and deployment.
A capable ASP.NET Web API specialist usually brings strong C#, .NET, HTTP and REST knowledge. Useful adjacent skills include Entity Framework Core, SQL, OpenAPI, automated testing, OAuth 2.0, Azure, Docker and CI/CD.
The right level for ASP.NET Web API depends on the project’s risk and scope rather than a fixed amount of experience. A small endpoint extension may need focused API and C# skills, while a migration or public service requires proven judgment in security, versioning, performance and operations.
Yes. ASP.NET Web API work is well suited to remote collaboration when repositories, environments, API specifications and deployment processes are accessible. Agree on review routines, working hours, documentation standards and whether German-language communication is needed for stakeholders.
Ask an ASP.NET Web API professional to explain a real API decision, including resource design, authentication, error handling and compatibility. Review examples of tests, OpenAPI documentation, monitoring and production support, and check whether the person considers the needs of both API consumers and operations teams.
ASP.NET Web API 2 can remain practical when a business system is tied to .NET Framework libraries or depends on an established hosting environment. It should be assessed alongside support requirements, security, integration constraints and the effort needed to move to ASP.NET Core Web API.
A strong ASP.NET Web API engagement may deliver endpoint specifications, implementation, automated tests, database or integration changes and OpenAPI documentation. Depending on the assignment, it should also include deployment configuration, logging, security notes and a clear handover for the internal team.
The average hourly rate of freelancers in Germany who have used ASP.NET Web API in their recent projects is 93 €, which corresponds to a daily rate of about 742 € based on an 8-hour working day.
Of the freelancers in Germany who have used ASP.NET Web API in their recent projects, 81% hold at least a Bachelor's degree, 46% hold at least a Master's degree, and 3% hold a doctorate.
On average, freelancers in Germany who have used ASP.NET Web API in their recent projects have 22 years of professional experience, with a single engagement typically lasting around 3.1 years.
The most common languages among freelancers in Germany who have used ASP.NET Web API in their recent projects are German (98%), English (98%), and French (15%).
The most common industries among freelancers in Germany who have used ASP.NET Web API in their recent projects are Information Technology (96%), Manufacturing (54%), and Banking and Finance (46%).
The most common business areas among freelancers in Germany who have used ASP.NET Web API in their recent projects are Information Technology (98%), Product Development (94%), and Quality Assurance (52%).
Main locations of FRATCH Experts, who have recently used ASP.NET Web API
Our freelancers and interim experts are at home across the DACH region — available on-site in the major business hubs or fully remote. Choose a location to discover matched specialists, local market insights and up-to-date availability.
Berlin Hamburg Munich Cologne Frankfurt Stuttgart Dusseldorf Leipzig Dortmund Essen Bremen Dresden Hanover Nuremberg Request a free demo
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FRATCH CEO
