Clean Architecture Experts in Berlin

• 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.

AI Platform Backend – Senior Developer

Hired to design and build an AI platform backend from the ground up, including multi-provider LLM orchestration and real-time infrastructure for AI influencer personas at scale.

Tasks and Responsibilities

• Architected and implemented a multi-LLM orchestration layer with Semantic Kernel to integrate GPT-4 and other providers for core platform logic and AI influencer personas, reducing model-switching overhead by abstracting provider APIs behind a unified interface.
• Designed and developed a backend from the ground up in C# / .NET 10, including domain modeling with DDD, a versioned RESTful API layer, and cloud infrastructure on Azure.
• Built real-time chat infrastructure with Server-Sent Events (SSE), message persistence, and delivery guarantees for running AI influencer personas live at scale.
• Developed a media management service with cloud object storage integration for uploading and retrieving influencer-generated content.
• Created an integration and unit test suite with data seeding for reliable regression testing across all core platform flows, significantly reducing the production error rate.

Tools and Technologies: C#, .NET, ASP.NET Core, Python, TypeScript, MySQL, Semantic Kernel, EF Core, Minimal APIs, LLM Orchestration, Prompt Engineering, Agentic AI, Generative AI, AI-Assisted Engineering, Claude Code, GitHub Copilot, Google Gemini, OpenAI API, Ollama, Redis, Azure, Azure Container Apps, Azure Database for MySQL, Docker, GitHub Actions, Clean Architecture, Vertical Slice Architecture, CQRS, Domain-Driven Design, REST API, xUnit, Integration Testing, Unit Testing, Jira, Confluence, Scrum

• Contributed to the architecture design process, resulting in scalable and maintainable solutions for complex projects.
• Enhanced app performance by optimizing code and implementing efficient algorithms.
• Stayed current with industry trends to ensure implementation of best practices in app development.
• Led a team of iOS developers for timely completion of projects and achieving client satisfaction.
• Translated basic design plans into full iOS app frameworks, delegating project components to appropriate team members.
• Estimated work hours and tracked progress using Scrum methodology.

• Designed and implemented a hybrid recommendation system (content-based + collaborative filtering)
• Built end-to-end ML pipelines including data processing, feature engineering, model training, and evaluation
• Developed RAG-based LLM systems using LangChain and vector databases for semantic search and knowledge retrieval
• Established MLOps workflows with MLflow for experiment tracking, versioning, and deployment readiness
• Implemented deep learning models (computer vision & classification) using PyTorch and TensorFlow

• Worked on the development of cloud-based web platform for different financial solutions (Payment by invoice, EPI, Freenet)
• Made technical and architectural decisions, discussed with management team the direction of the platform
• Provided technical expertise, made software improvements
• Participated in meetings, reviewed tickets, wrote documentation
• Technologies used: C#, .NET, MS Azure Services, Azure SQL, CI/CD, Azure DevOps, Jira

• Built marketing site for video app launch
• Implemented responsive UI and performance optimizations

• 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.

• Architected RESTful APIs and microservices using .NET Core.
• Designed and managed SQL Server and Cosmos DB databases.
• Developed responsive frontends with Angular, Bootstrap, and TypeScript.
• Deployed and managed Azure cloud infrastructure.
• Implemented unit tests for both backend and frontend modules.

• 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

• Optimized the Amp healthcare app alongside a senior developer, specifically enhancing data caching mechanisms which led to a 25% improvement in load times.
• Applied MVI architecture, resulting in a 30% decrease in bugs and streamlining testing processes.
• Implemented CI/CD with Bitrise, reducing deployment sizes from 120MB to 104MB.
• Led the migration of 40% of the Java codebase to Kotlin.
• Achieved 85% unit test coverage.

• Developed a SolidJS frontend UI for a spectrometric water analysis system on an ARM-based embedded Linux platform
• Prototyped UI in TypeScript React/Nx with LitElements and MQTT integration
• Built production UI using SolidJS, SUID, i18next, Ajv, MQTT.js, C3.js
• Refined requirements with UX team and water analysis system engineers
• Defined and documented system architecture, MQTT message formats, frontend architecture, and development setup
• Set up frontend system from scratch, implemented domain-oriented type system, UI components, and application state
• Managed MQTT pub/sub services and schema-based message validation in frontend
• Coached two junior frontend developers
• Worked in an agile remote team using JIRA, Git, and Bitbucket

• Heycar is a leading automotive platform redefining the used car market through intelligent data pipelines, multi-tenant services, and dealer-focused tooling. I led initiatives across backend architecture, data ingestion, and identity management to enhance scalability, reliability, and developer productivity.
• Ingestion Platform: Designed a unified ingestion platform with YAML-based configuration, enabling new dealer data pipelines to be onboarded without code changes, cutting setup time from ~2 months to 2-3 days and improving scalability by 40%.
• Keycloak Leadership: Acted as the company's Keycloak expert, scaling it for multi-tenant identity management and extending functionality with custom plugins and delegated admin APIs.
• Back-Office Tooling: Developed a back-office application integrated with Salesforce, enabling dealers to manage inventory, convert leads, and handle support requests in real time.
• Multi-Tenant Migration: Collaborated across backend teams to migrate Heycar's core services into a unified multi-tenant cluster, ensuring high availability.
• Frontend CI Optimization: Optimized monorepo delivery by implementing CircleCI dynamic config with NX, deploying only affected UI projects and drastically cutting build times.
• Observability & Mentorship: Enhanced monitoring and release reliability while mentoring backend engineers and improving code review standards.

• Leading architecture and delivery of AI-powered educational content platform, managing two development teams with full technical ownership.

• Designed and architected the Content Hub platform replacing legacy SiteFusion systems, enabling professors to create AI-assisted learning materials for improved student outcomes.

• Established technical strategy, defined architecture requirements, and aligned two cross-functional teams (AI Media Team, TEAQ Team) on a unified delivery roadmap.

• Implemented Clean Architecture principles and AI-agent-friendly documentation standards across the engineering organization.

• Drove adoption of modern development workflows including CI/CD automation and MongoDB-based content management solutions.

• Own Azure-hosted ASP.NET Core microservices for chronic-care workflows, sustaining 99.8% uptime across 3,000+ patient interactions.

• Shape HL7 FHIR-based patient, encounter, and observation profiles delivering a unified source of truth for clinical teams and integrations.

• Implement SignalR telemetry, Application Insights alerting, and automated pipelines that surface deteriorating vitals in under three seconds.

• Automated consultant outreach by orchestrating Twilio voice campaigns via n8n workflows and VAPI AI assistants, boosting successful client contacts by 55%.

• Entlass Manager: Led the end-to-end build of the chronic-care coordination platform, standing up Azure-native microservices, clinical data flows, and patient-facing tooling from initial requirements through production release.

• Power Dialer: Built the Twilio-driven consultancy auto-dialer and n8n workflows, raising client reachability to 85%.