Software Engineer & Consultant

Hello, I'm
Fabian Blum

I'm a

Full Stack Developer focused on .NET, microservices, cloud architectures and AI-driven development.

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Fabian Blum – Senior Software Engineer & AI Engineering Specialist

About

Full Stack Developer & Software Engineer

During my studies I worked intensively with the .NET stack to deliver a variety of projects. After graduating I applied and extended these skills in the logistics industry and e-commerce.

Across these projects my work has focused on interfaces between systems. I have also delivered Android and iOS apps as well as web applications for clients.

Today my work centers on microservices with Azure Service Bus, REST APIs on .NET Core and DevOps with Kubernetes, Azure DevOps and Terraform.

A growing focus of my work is AI-driven development: a structured engineering approach with central agent rules, domain-specific context, security guardrails and a reproducible flow of Context Engineering, implementation and validation.

Quick facts

Location

Witten, Germany

Degree

B.Sc. Medical Informatics

Technology stack

.NET / C#

Experience

9+ years

Email

contact [at] fabian-blum.de

Mobile

+49 160 95852230

Skills

I have used a wide range of technologies and stacks across my projects. My focus is the .NET stack and AI-driven development.

Current focus

Every technology from active project work — the bars show my current focus.

Development

.NET Core / EF Core / C#
Blazor
HTML / CSS & JavaScript
Xamarin / MAUI
Angular

Databases & DevOps

MongoDB
MSSQL
Azure DevOps / GitHub Actions
Azure / Kubernetes / Terraform
Docker

AI Engineering & Agents

Claude Code
OpenAI Codex
Agent structures & multi-agent setups
Context Engineering
GitHub Copilot

Additional tools & standards

MicroservicesREST APIsAzure Service BusOAuth 2.0OpenID ConnectKeycloak integrationKeycloak administrationShopware HeadlessJetBrains AIGit
Focus area

AI-driven development

My approach combines clear context, explicit rules, validated implementation and clean documentation into a reproducible development mode. AI becomes a structured part of a resilient engineering process — deliberately guided, controllable and scalable in the long run.

Context Engineering

Building the right context instead of throwing information at the model. A central rule base, local domain guides and selectively loaded references substantially reduce hallucinations.

Instruction Design

Architecture, coding conventions, definition of done and security boundaries are formalized as agent rules. AI output then fits the existing codebase consistently.

Agent Governance

AI is treated as an operational agent with clear boundaries, responsibilities and escalation points. Strategic and domain decisions remain with humans.

Architecture-aware usage

AI reinforces existing patterns, domain boundaries and technical standards instead of undermining them. Multi-agent capable across GitHub Copilot, JetBrains AI, Claude Code and other tools.

Safe production usage

Hard guardrails for secrets, sensitive data and security-critical actions. Validation-driven implementation instead of blind trust in model output.

Reproducible flow

Context, implementation, validation and documentation interlock. It is not the single good answer that counts but a mode that delivers repeatedly good results.

My working mode

Four steps that turn every AI usage into a traceable engineering outcome.

01

Locate the context

Map the task to the right domain and technical area before any code is written.

02

Load rules & references

Central rule base, local guides and referenced code locations are read deliberately — not guessed from model knowledge.

03

Follow patterns

Established patterns such as Result<T>, FluentValidation, DI and Mapster guide the implementation.

04

Validate & document

Builds, tests and downstream effects on indexes, policies and APIs are part of the work, not an afterthought.

Good AI usage in software engineering does not start with a great prompt. It starts with a good system. That is exactly where my focus lies.

Resume

I have broad experience as a software engineer with a focus on the .NET stack. My career spans various industries including logistics and e-commerce.

Professional experience 2024 - Today

Senior Software Engineer

VELO DE VILLE (AT Zweirad GmbH)

  • Development of a .NET Core backend with Microsoft Dynamics NAV integration
  • REST interfaces for the VeloWallet app with a focus on performance
  • MSSQL and MongoDB as database technologies
  • Self-contained synchronization services between systems
  • Microsoft Business Central integration
  • Frontend-backend integration and API design
  • API integration of a Shopware-based headless dealer portal
  • Implementation of Shopware impersonation and Keycloak integration for dealer authentication and user switching
  • OAuth 2.0 / OpenID Connect with a Keycloak server
  • Building an AI-driven development environment with a central agent rule architecture (AGENTS.md, local domain guides, multi-agent compatibility)
Professional experience 2024 - Today

Freelance Software Developer

Freelance, Witten

  • Full stack .NET development and consulting
  • AI-assisted development with context engineering, agent rules and safe production usage
  • Identity management systems (OAuth 2.0 / OpenID Connect)
  • Data migration and quality assurance
Professional experience 2020 - 2024

Senior Software Engineer

Parfümerie Douglas, Hagen

  • Microservices for CRM and e-commerce with .NET 6+ and MongoDB
  • Integration of SAP Customer Data Cloud
  • DevOps with Azure DevOps, Kubernetes and Terraform
Professional experience 2017 - 2020

Full Stack Developer

proLOGiT GmbH, Dortmund

  • Web and mobile app development (Razor Pages, ASP.NET MVC, Xamarin)
  • Further development of the catkin logistics platform
  • Identity Server implementation (OpenID Connect & OAuth2)
Education 2014 - 2018

Bachelor of Science - Medical Informatics

Dortmund University of Applied Sciences and Arts

Learned C# / .NET in various practical projects. Also NoSQL databases (MongoDB, RavenDB, OrientDB) as well as agile development methods such as SCRUM and Kanban.

Education 2011 - 2014

Applied Computer Science

Dortmund University of Applied Sciences and Arts

Studies in cooperation with the Robert-Bosch-Berufskolleg. In 2014 I switched to medical informatics.

Education 2007 - 2011

Information Technology Assistant

Robert-Bosch-Berufskolleg Dortmund

School-based vocational training with university entrance qualification. Focus: Java, networking, MySQL.

Services

Drawing on broad experience, I'm available for consulting to identify the right steps for successful project delivery and to implement them professionally.

Application Development & Consulting

Analysis and development of web applications, interfaces and software modules on .NET. New implementations or optimization of existing processes.

Data Exchange & Interfaces

Delivering important business data at the right point of your process. Intelligent data management for new business areas.

Identity Management

Setup of OAuth 2.0 / OpenID Connect servers. Central login via an identity management system / single sign-on (SSO).

Data Migrations

Targeted data preparation and documentation during system migrations. Faster value while improving data quality.

Performance & Quality Assurance

Optimization of existing applications, processes and databases. Professional development methods, tests and documentation.

AI-assisted Software Development

Consulting and building AI-driven development processes — from central agent rules through context engineering and instruction design to safe production usage.

Contact

If you have questions or project ideas, feel free to get in touch.

Address

Finefrauweg 11
58455 Witten
Germany

Email

contact [at] fabian-blum.de

Mobile

+49 160 95852230

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