Full Stack Developers

Complete build of a B2B SaaS platform for recruitment agencies

• Multi-source job aggregation via ATS APIs
• AI-assisted career page scraping
• Rule-based and AI-assisted matching
• Credit-based monetization model with Stripe integration
• Live in production since July 2026

Tech stack

• NestJS
• React
• PostgreSQL
• pgvector
• Claude AI
• Prisma

• Designed and developed a multi-tenant SaaS platform enabling organizations to build their own knowledge bases and chat with brand-customized AI assistants (white-label approach with dynamic branding per organization).
• Implemented a scalable RAG architecture with a GPT-4o tool-use loop, hybrid semantic search, and strict tenant isolation at database and search index level.
• Built persistent, project-like chat sessions including a streaming API (SSE), multilingual support, and speech input/output (STT/TTS).
• Delivered the cloud infrastructure as Infrastructure-as-Code, fully automated per-customer CI/CD pipelines, and an onboarding process for new tenants.

Technologies used: Python, FastAPI, Pydantic (v2 noted), Next.js, React, TypeScript, Tailwind CSS, OpenAI / LLMs (GPT-4o), Azure AI Search, Cosmos DB, Azure Blob Storage, Azure Cognitive Services Speech, Azure App Service, Azure Container Registry, Retrieval-Augmented Generation (RAG), Server-Sent Events (SSE), Docker, Terraform, GitHub Actions, REST, OpenID Connect (OIDC), Multi-Tenancy

• A digital system made up of special software and hardware components. The overall system replaces the traditional process with job slips and handwritten notes and enables more efficient order intake. Orders and work steps for the violin-making company’s projects can now be recorded, processed and logged in real time directly on the workshop’s touchscreen PC, by mobile phone or on the desktop. This gives customers a more transparent view of the work on their instruments and allows them to track the status and progress of their instrument through their customer account.

Tech stack: next.js, React, Flutter, Dart, Raspberry, Linux, Directus

• Own full-stack development of an AI-native enterprise platform built on TypeScript, React, Vite, tRPC, Hono, and PostgreSQL, delivering AI-powered consulting workflows to B2B clients.
• Designed and shipped a multi-agent AI system using ReAct framework and Claude skills-style workflow patterns, including an intelligent PM assistant with rich system prompts, slash commands, tool integrations, and streaming chat UI.
• Architected an LLM evaluation framework: rubric-based LLM-as-judge, golden datasets, regression testing, and automated quality gating — ensuring consistent AI output quality at scale.
• Integrated LangFuse for end-to-end LLM tracing, conversation replays, and evaluation pipelines, enabling data-driven prompt optimisation that reduced token costs and response variance.
• Built with Drizzle ORM, pgvector, and knowledge graphs for structured data access, semantic search, and relationship-aware AI reasoning across the platform.
• Led TanStack React Query migration across the application — replacing manual state management with centralised caching and automatic refetching, reducing data-fetching boilerplate significantly.
• Practiced AI-native development throughout: Claude Code, Codex, Perplexity SDK, and LLM-assisted testing across the full development lifecycle. Deployed on Vercel + Azure ACA with Biome for linting/formatting.

Independent, part-time open-source engineering focused on build-time tooling for Next.js, React, MDX, and JavaScript/TypeScript compiler pipelines.

• Built next-slug-splitter to optimize content-driven Next.js applications. It analyzes MDX content at build time, resolves component usage, and generates route-specific handlers so pages avoid sharing the full catch-all component bundle.

• Created supporting plugins and utilities for scoped MDX transformations, nested component dependency resolution, compile-time refinement, safe ESTree evaluation, and object-graph diffing.

• Own architecture, API design, implementation, automated testing, npm publishing, documentation, demos, and performance benchmarking.

Building blocks:

• remark-scoped-mdx: Context-aware AST transformations with nested scope isolation, typed component registries, and prop inference.

• recma-component-resolver: Dependency-graph analysis and selective component forwarding across nested MDX includes.

• recma-static-refiner: Build-time prop extraction, schema validation, derivation, and pruning.

• estree-util-to-static-value and object-graph-delta: Safe static evaluation and deterministic, cycle-safe structural diffing.

Tech Stack:

• Frameworks: TypeScript · Next.js · React · MDX

• Compiler tooling: Unified · Remark · Recma · MDAST · ESTree · ts-morph · esbuild

• Competencies: Static analysis · AST traversal and transformation · dependency graphs · code generation · schema validation · route and bundle splitting

• Tooling: Vitest · tsup · npm · performance benchmarking

• Designed, built, and launched an internal event planning web application used by over 100 department leads for a large event, despite having no dedicated testing phase.

• Ensured smooth, failure-free operation during first production use, leading to the tool being adopted for future events.

• Automated catering calculations and related workflows, significantly reducing email communication and manual computation effort for meal planning.

• Managed deployment and hosting on a Linux server using Coolify, including application setup and runtime operations.

• Hired and guided a communication designer on UX while independently owning all technical decisions and implementation.

• Short description: Lead of a group-wide project to establish standardized cloud governance for Microsoft Azure, including policies, security and compliance controls, automation, and cost and operations management, while maintaining the autonomy of decentralized business units within regulatory frameworks.

• Tasks and activities:

• Overall responsibility for the design, setup, and implementation of a company-wide cloud governance structure (Azure), including target picture, roadmap, and operating model.

• Management of internal and external stakeholders (C-level, IT, Security, Compliance, Cloud Architecture, DevOps), including decision and escalation management.

• Planning and facilitation of workshops on cloud strategy, governance principles, and the design of areas such as Identity, Connectivity, and Platform Management.

• Definition, implementation, and rollout of cloud policies (Azure Policy / custom policies), security standards, and compliance requirements (including GDPR, ISO 27001, BSI C5).

• Building a cloud governance framework based on the Azure Cloud Adoption Framework (CAF), including landing zone and guardrail concepts.

• Introduction of automation solutions for governance, security, and cost control (policy/control automation, IaC, CI/CD-based control mechanisms).

• Implementation of cloud security and compliance monitoring mechanisms as well as continuous improvement processes.

• Establishment and operationalization of FinOps in an enterprise environment (central and decentralized FinOps teams), including cost management strategies, reporting, and guardrails.

• Integration of governance policies into DevOps processes (e.g. CI/CD principles for security and compliance checks, GitLab Runner concept in spokes, GitLab CI/CD for CAF landing zones).

• Implementation of access concepts including RBAC design and "breaking glass" mechanisms (emergency access) as well as certificate automation (ACME / step-ca).

• Achievements:

• Created a consistent, auditable governance and control set for Azure (policies, standards, compliance mapping), laying the foundation for scalable cloud usage in a regulated environment.

• Established repeatable automation for governance, security, and cost control (IaC + CI/CD), reducing manual effort and implementation risks.

• Improved operating and decision-making capabilities across central and decentralized units (clearer roles, responsibilities, escalation paths, balance between autonomy and corporate rules).

• Significantly increased workload compliance during lift-and-shift migrations.

• Technologies used:

• Microsoft Azure Policy, custom policies.

• Terraform, OpenTofu, Terragrunt.

• step-ca (ACME).

• Entra ID.

• Azure Firewall.

• Azure networking, hub-and-spoke architecture.

• Azure vWAN (evaluation).

• Azure Front Door, Azure Application Gateway.

• Azure ExpressRoute.

• Azure Key Vault.

• NetBox.

• GitLab (on-premises).

• Infrastructure, concepts used:

• Cloud Shared Responsibility Model.

• Hub-and-spoke connectivity / central shared services (from hub-spoke context).

• Central governance with decentralized delivery (business unit autonomy with guardrails).

• Methods used:

• Scrum.

• Stakeholder management (C-level to engineering).

• Cloud governance, Azure Cloud Adoption Framework (CAF).

• DevOps, CI/CD.

• Cost and FinOps approaches: tagging/chargeback models, budget/alert concepts, reserved instances/savings plans vs. on-demand scenarios, sensitivity analyses.

• RBAC, "breaking glass" concepts.

• ACME / certificate automation.

• GitLab Runner concept in spokes, GitLab CI/CD pipelines for CAF landing zones.

• 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#

Lead developer of the frontend and backend systems for a web-based pre-sales tool. It is used by sales staff and engineers to configure and calculate complex measurement systems for industrial customers. Core features include a collaboration platform, a product configurator, physical feasibility checks, and a PDF generator.

TypeScript · Node.js · Nest.js · Angular · REST · MongoDB · Playwright

Project for a leading German email and cloud service provider: As Senior Frontend Developer and Technical Web Architect, I developed an international, multi-tenant white-label consent management layer for several brands.

Main tasks:

• Architecture and implementation with Vue 3, TypeScript, and Vite
• Development of automated tests with Vitest and Playwright
• Creation of brand-specific CMP configurations, CSS themes, i18n structures, and vendor settings
• Implementation of the playout and initialization logic as well as backend integration
• technical decision support, project and code documentation

Impact: Replacement of external CMP solutions with a reusable and long-term maintainable in-house base for several international brands and rollouts.

Technologies: Vue 3, TypeScript, Vite, Vitest, Playwright, IAB TCF, Google Additional Consent, i18n, Git, CI/CD.

• E-Commerce Marketplace Platform (Austria) | 04/2025 – 07/2026: Refactored and extended a scalable marketplace solution with React, Node.js, Stripe and Sendcloud integrations; connected to a headless CMS for flexible content management

• Real Estate Search Platform (Germany) | 10/2025 – 12/2025: Integrating Keycloak as an IAM provider into one of Germany’s largest real estate search platforms; set up Keycloak instances for various stages; modified the existing authorization and authentication logic in two frontend clients (Next.js) and one backend service (Node.js); integrated various IdPs into Keycloak

• Automotive SaaS Platform (Austria) | 09/2023 – 04/2025: Extended and optimized performance of one of the largest SaaS solutions for car dealerships in the DACH region (React, Node.js); migrated critical services to AWS (Lambda, S3, CloudFront, etc.); integrated various legacy interfaces from the automotive industry

• PLM Platform Textile Industry | 02/2023 – 09/2023: Lead developer of a 4-person engineering team; responsible for overall architecture of a Product Lifecycle Management solution; delivered Mobile App (React Native), Web Application (React) and Backend Services (Node.js/Nest.js) via DigitalOcean and Google Play Store

• SaaS Backend Optimization (Germany) | 08/2022 – 03/2023: Enhanced performance and extended existing Node.js/Nest.js services; implemented comprehensive end-to-end tests for quality assurance

• Enterprise Dashboard Energy Sector (Germany) | 09/2021 – 08/2022: Developed a modular dashboard solution for integrating existing enterprise applications; implemented real-time data visualization via message broker architecture; achieved >95% test coverage in frontend and backend using .NET Core 3, PostgreSQL, Docker, RabbitMQ, Angular and Keycloak

• Other projects: IoT-Dashboards (Grafana, SQL, .NET Core 3) | Self-hosted social media app (Angular, Nest.js, Ionic) | Recommender-App for coffee roastery (angular, Touchscreen optimized)

• Led the end-to-end delivery of enterprise full-stack web applications by driving requirement analysis, solution design, frontend and backend development, database design, API integration, code reviews, team coordination, Agile execution, CI/CD deployments, production support, performance optimization, security implementation, and stakeholder collaboration to deliver scalable, high-quality software solutions.

• Opt-in RAG extension over tenant-owned data sources (SharePoint, Confluence) on existing multi-tenant enterprise AI platform
• Architecture: ADRs, solution evaluations, permission strategy, cost modeling
• End-to-end SharePoint and Confluence connectors: OAuth consent flows, token refresh, metadata sync, search integration
• Permission resolution: ACL indexing at ingestion and query-time verification (document-level security)
• Elasticsearch hybrid search (semantic + keyword) with RRF scoring
• RAG chat with context injection and source citations
• Stack: Elastic Cloud, Elasticsearch, Docker, Northflank, Next.js, React, TypeScript, Prisma, Microsoft Graph API, Atlassian REST API, OAuth 2.0

• Evaluate AI-generated software solutions to improve the coding capabilities of advanced large language models.
• Review code generated by AI systems across Python, JavaScript, TypeScript, Java, C++, and Rust.
• Analyze software implementations for correctness, readability, maintainability, scalability, security, and adherence to professional engineering practices.
• Create and solve complex software engineering tasks covering debugging, system design, API development, algorithms, databases, testing, and architecture decisions.
• Develop detailed explanations and feedback highlighting coding mistakes, edge cases, performance issues, and better engineering approaches.
• Design realistic programming scenarios that test AI models' ability to understand and solve real-world software engineering problems.
• Evaluate AI responses against defined technical criteria and create high-quality reference solutions.
• Identify failures in AI reasoning including incorrect assumptions, incomplete implementations, security vulnerabilities, and inefficient approaches.
• Provide expert feedback used to improve AI model training datasets and evaluation benchmarks.
• Apply professional software engineering experience from financial, healthcare, and distributed systems environments to assess AI-generated solutions.

Technical Focus: LLM Evaluation, AI Coding Models, Software Engineering Tasks, Code Review, Debugging, Python, JavaScript, TypeScript, C++, Rust