11/10/2026 updated
40 % partially available
Senior .NET/C# Developer & Architect | Microservices, SQL Server Performance, Angular/React/Vue
Maribor, Slovenia
Only remote
B.Sc in Computer ScienceAbout me
Senior .NET/C# developer and architect with 8+ years of full-time experience. I modernize legacy systems into web architectures, design microservice backends (90+ services) and fix slow SQL Server queries (12s to under 40ms). Angular and Vue.js on the frontend. Fluent in German and English.
Clean Code PrinciplesASP.NETApplication Programming Interfaces (APIs)Architectural DesignC Sharp (Programming Language)Software QualityCode ReviewData SecurityData StructuresDebuggingDesign Elements and PrinciplesWeb DevelopmentDistributed SystemsEntity FrameworkMicrosoft Servers
Senior .NET/C# developer and architect with 8+ years of full-time experience (freelancing since 2009). I build and modernize business applications end to end: backend services, databases and web frontends. Based in Maribor, Slovenia, working remotely. German C2, English C1.
CORE SKILLS
- Backend: C#, .NET 10 / ASP.NET Core, REST APIs, microservices, modular monoliths, DDD
- Databases: MS SQL Server (T-SQL, query tuning, execution plans, Query Store), MySQL, database design
- Frontend: Angular, AngularJS, Vue.js 2 & 3, React, TypeScript, JavaScript, ag-Grid
- Testing and delivery: integration tests, Playwright end-to-end tests, code reviews, Git, Docker, CI/CD with TeamCity and Azure DevOps
- AI-assisted development: daily work with coding agents in agent mode (Claude Code)
EXPERIENCE HIGHLIGHTS
- Legacy modernization: led the migration of a monolithic desktop application for production monitoring, machine control, reporting and workflows to a web architecture used by 30+ clients and 400 to 600 users. Designed the backend as 90+ independently deployable microservices in C# and MS SQL Server and built the Vue.js frontend foundation (component library, design system).
- Performance engineering: re-architected an OEE data aggregation service, cutting query times from 30s to 0.3s. On an enterprise platform, traced 30s timeouts to a query-plan regression on a 54-million-row table and cut the query from 12s to under 40ms.
- Enterprise SaaS: currently extending an enterprise marketing platform on .NET 10 and Angular: budget and cost planning features, a workflow engine with configurable limits and webhook handling, and an AngularJS-to-Angular migration.
- Public sector: joined a national education platform during go-live and stabilized it through rapid refactoring and bug fixes. Built hierarchical access control mapping users, regions and schools.
- Security and licensing: designed a decentralized licensing system that validates entitlements across microservices with public/private key cryptography.
- DevOps: configured the TeamCity build pipelines for the microservices and built a parameter-driven setup project that generates each service's installer for one bundled installation.
- Team leadership: led and mentored a team of 3 developers (code reviews, task planning, coding standards).
HOW I WORK
I am used to joining running projects and becoming productive in an existing codebase quickly. I back changes with automated tests and communicate directly with stakeholders in German or English.
EDUCATION
BSc in Computer Science (University of Maribor). MCSA: Web Applications (Microsoft, 2020).
Experience
Professional experience10+ years
Freelancer since2010
Languages
GermanFluentEnglishFluent
Project history
Freelance software architecture and development (C#/.NET, MS SQL Server, web frontends) for clients in industrial automation and the public sector.
- Performance engineering (industrial automation): analyzed and re-architected an OEE data aggregation service; restructured the SQL so that query times dropped from 30s to 0.3s.
- Go-live stabilization (public sector): joined a national education platform during its go-live phase; analyzed and resolved issues reported by the Ministry and public users through rapid refactoring and bug fixes.
- Access control: designed and implemented hierarchical assignment algorithms that map users, regions and schools and derive data access permissions automatically from geographic identifiers.
- Security and licensing: designed a decentralized licensing system that validates entitlements across a microservices landscape using public/private key cryptography.
- End-to-end responsibility as a sole contractor: clarifying requirements with clients, technical design, implementation and delivery.
Senior full-stack engineer and team lead for a production monitoring and control platform in industrial automation (C#/.NET, MS SQL Server, Vue.js).
- Legacy-to-web migration: led the migration of a monolithic desktop application for production monitoring and configuration, machine control, reporting and workflows to a web architecture used by 30+ clients and 400 to 600 users.
- Backend architecture: designed and implemented a microservice backend in C# and MS SQL Server and split the business logic into 90+ independently deployable services.
- Frontend foundation: built the Vue.js frontend from scratch, including the core component library, design system guidelines and layout structure used by the whole team.
- Build and release automation: configured the TeamCity build pipelines for the microservices and built a parameter-driven setup project that generates each service's installer for one bundled installation.
- Team leadership: led and mentored a team of 3 developers; responsible for code reviews, task planning and coding standards.
Freelance full-stack web development for various clients (2009 to 2018), combined with a professional tennis career on the ITF Men's Circuit (2006 to 2018) and computer science studies.
SOFTWARE DEVELOPMENT
- University collaboration platform (PHP, MySQL): designed and built a platform with forums, event management and file sharing; used daily by a university class for over 4 years.
- Custom web applications: built client-specific web applications with PHP for the backend and Node.js for asynchronous tasks.
- Frontend development: implemented responsive user interfaces with JavaScript (jQuery), HTML5 and CSS3, including cross-browser compatibility.
- E-commerce: set up and customized OpenCart shops, integrated payment gateways and adapted themes.
- End-to-end responsibility for each client: requirements, implementation and deployment.
PROFESSIONAL TENNIS
- Competed professionally in singles and doubles; career-high ATP rankings of No. 1595 in singles and No. 1014 in doubles.
- Won 4 Slovenian national championship titles (2 singles, 2 doubles) and 2 further national singles tournaments.
- Transferable strengths: discipline, time management and decision-making under pressure.