REST API Experts in Stuttgart

• Focus: system architecture, cloud-native platforms, microservices, API design
• Product: Pflege-Pfad is a digital matchmaking platform that connects relatives of people in need of care directly with verified care services and caregivers - without an agency and without ongoing fees.
• Business analysis & process design:
• Analysis of the German care market and identification of the key pain points of both target groups.
• Modeling of the core business processes: registration, verification, care request, application, placement, and rating.
• Definition of the business model as a freemium/premium model with optional contact unlocking.
• Creation of user stories and requirements documentation for relatives, care services, and administrators.
• Design of trust and quality assurance mechanisms with document upload, admin review process, and rating system.
• Coordination with stakeholders and validation of product decisions with potential users.
• Technical implementation:
• Design and implementation of the entire platform architecture as a solo developer.
• Design and implementation of a REST API with Spring Boot and Kotlin, including JWT-based authentication.
• Development of the frontend as a single-page application with Angular 17.
• Implementation of the AWS infrastructure with EC2, RDS PostgreSQL, S3, CloudFront, and IAM.
• Document upload with AWS S3 via presigned URLs for verification of care services.
• Email notifications via Resend API.
• AI-supported care service search via OpenAI API.
• Implementation of complete user flows such as registration, login, password reset, and placement process.
• Building an admin panel for user and care service management as well as analytics.
• CI/CD with GitHub Actions and containerized deployments with Docker.
• End-to-end tests with Playwright.

Technologies: Kotlin, Spring Boot 3, Spring Security, JWT, JPA/Hibernate, PostgreSQL, Angular 17, TypeScript, RxJS, AWS (EC2, ECS, S3, CloudFront CDN, RDS PostgreSQL, IAM), nginx, GitHub Actions, Playwright, Maven, Git, OpenAI API, Resend API, Docker, Scrum, i18n (DE/EN/TR), Kiro, feature-flag architecture.

• Development and introduction of operations processes
• Preparation of complete documentation packages (including incident management and operations support) to meet compliance requirements
• Introduction of a workshop on IaC (Infrastructure as Code)
• Technical consulting for the project security concept (ISMS)
• Installation and operation of Kubernetes clusters on AWS, on-prem, and Azure
• Hybrid cloud architecture design (on-prem, Hetzner, AWS)
• Analysis and troubleshooting of incidents and system outages
• Network adjustments for firewall rules, gateways, OpenVPN settings, and IPsec tunnels (pfSense)
• Technical consulting on Bitbucket, Jenkins, and GitLab CI/CD pipelines
• Consulting on Ansible deployments and infrastructure automation
• Consulting on building a scalable system in the cloud (AWS / Azure)
• Technologies / Tools: Ansible, Terraform, AWS, Azure, VPN, pfSense, Jenkins, Bitbucket, Kubernetes, GitLab Runner, ISMS, Golang, Prometheus, Grafana, S3, Lambda, RDS, ECS, Cognito, OIDC, Harbor, MinIO, Postgres, Redis, Keycloak, Ceph, Proxmox, CloudFormation, PostgreSQL, Flux CD, Hetzner, IONOS, Sonatype Nexus Repository, Entra ID, Dex IdP, Pulumi

Designed and developed an AI-powered automation platform using n8n to analyze social media niches, identify target audiences, and automate marketing strategy generation. The solution combined AI agents, workflow orchestration, and data analysis to automate research processes and generate data-driven insights.

• Designed and implemented complex automation workflows using n8n
• Developed AI-powered analysis agents for market and audience research
• Integrated multiple APIs and AI services into automated workflows
• Built automated market, competitor, and target audience analysis pipelines
• Leveraged Large Language Models (LLMs) for information summarization, classification, and prioritization
• Containerized and deployed the platform using Docker

Technologies: n8n, AI Agents, OpenAI APIs, Prompt Engineering, LLMs, Docker, Linux, REST APIs, Webhooks

• Developing the infrastructure and improving existing infrastructure: Jenkins, Gitlab Pipeline, OpenShift, Docker, Helm Chart, Kubernetes, Artifactory, CodePipeline, CodeArtifact, Python
• Documenting solutions in Jira/Confluence
• Supporting other colleagues in different technical areas

• Development of a SaaS platform for esports teams with roles, scheduling, statistics, and billing
• Planning and implementation of the architecture, external API integrations, and operations
• Stack: Laravel 13, React 19, TypeScript, PostgreSQL, Redis, and Stripe

Two complementary tracks: (a) building my own AI products and open-source tools under the Neckarshore AI brand, with a focus on AI-supported multi-agent development processes and documentation automation; (b) freelance support for industrial, logistics, and financial companies in IT-related transformation projects.

Current product portfolio under the Neckarshore AI brand:

• Omnopsis Documenter — AI-powered documentation engine: generates compliance, technical, and release documentation from Git, Jira, and Confluence. 500+ automated tests, 100+ API endpoints, RBAC, monitoring stack.
• TrustScope — trust analysis for public GitHub repos: deterministic three-pillar report (Security & Supply Chain, Governance, Community) based on OpenSSF Scorecard, with constructive fix suggestions instead of a single misleading score.
• md-viewer — dependency-free Markdown viewer for macOS (Finder Quick Action) and web, split view of rendered document and raw text.
• Obsidian Vault Autopilot — AI-supported vault automation for Obsidian × Claude Code: sorts the inbox, renames notes, enriches frontmatter.
• Phonesis Voice Bank — voice archive for families, hospices, and cultural archives (guided recordings, inheritable archive, optional voice cloning); currently in the GDPR compliance phase (Art. 9, biometric data).
• Multi-Agent Development Process — 12+ specialized agents (architecture, implementation, security, refactoring, marketing) with structured handoff protocol, parallel execution, and automated quality assurance — powers the entire product development.
• Freelance consulting: Technical Product Ownership for production, logistics, and compliance/AML systems; steering international rollouts including test, cutover, and change management.

Stack: NestJS, TypeScript, PostgreSQL, Redis/BullMQ, Next.js, Claude Code (Opus), Docker, GitHub Actions, Vercel

• Develop hardware drivers and middleware using C++11, Java and Python
• Design of various RF features such as deembedding based on stakeholder requests
• Work with multiple teams to design drivers for multiple RF products
• Perform HW control to deliver RF signals and measure modulated response
• Develop RF drivers for generation of low noise signals to test WiFi7 products
• Use digital modulation techniques such as QAM for low level driver development
• Develop low level USB drivers for device enumeration
• Develop drivers for HW relay control of control boards for device testing
• Perform JTAG operations on devices under test
• Use network-based protocols (SFTP, UFTP, FTP, SSH) for control board communication
• Manage HW devices such as BADC and EEPROM for control board maintenance
• Utilize C++11/14/17 features, template metaprogramming and STL
• Employ multithreading for testing and control of multiple HW devices
• Develop tools for deployment of customer OS on control boards
• Perform component and integration tests using CxxTest
• Follow Scaled Agile Framework for software development
• Create detailed design documents using PlantUML

• Design, planning, and test case analysis
• Integration testing
• Coordination of UAT in the lab and on site
• Creation of HW and SW test catalogs
• Communication of test results from REST services with the SAP team
• Support for branches in the EU until rollout
• Coordination of defect management and SW updates with the involved vendors
• Checking the configuration of the charging stations in the backend software for different countries
• Continuous reporting of the quality status to project management
• Documentation of the user manual in English and German
• Tools: Confluence, be.Energised, OCPP Postman, OPI, CCV (payone.elavon), Excel, it4you

• Consulting, design, analysis, software architecture and development
• Designing, developing, and implementing a Pimcore environment and connecting multiple external API systems in a Kubernetes environment, as well as various PIM and ERP systems
• Technologies: Unix environment, design, Symfony development, PHP 8+, software architecture, MySQL/SQL, shell scripting, Git DevOps tasks, AI coding support, Pimcore 12, Shopware 6
• Team size: >10 people

• Implementing applications with Kotlin and Ktor as microservices
• Using MongoDB in the MongoDB Atlas cloud
• Asynchronous communication of services via Google Pub/Sub
• Using Kotest and MockK for unit tests
• Developing an administration frontend with TypeScript, React and Express.js
• Provisioning environments in GCP using Terraform
• Implementing CI/CD processes with GitHub Actions
• Operating scalable production and test environments in GCP with Kubernetes, Helm and Flux CD
• Monitoring environments with Prometheus and Grafana
• Providing BI data in the Google BigQuery data warehouse

• Designing the migration strategy for WLS applications to the BKA cloud and Stack IT

• Creating a hybrid cloud for internal testing and development with Kubernetes

• Transforming the IT landscape from a legacy monolithic architecture to a cloud-based architecture

• Integrating new CI/CD processes using Azure Pipelines

• Quadrupled the throughput of personnel security checks

• Migrated personnel security clearance applications to Docker-based applications

• Built CI/deploy pipelines with Azure DevOps

• Environment: Java Spring Boot, Kubernetes, Oracle WebLogic, OpenID, Camunda, JUnit, TOGAF

• Investigating the PoC and replacing and refining an existing cloud and IoT power plant control solution for certificate management of renewable energy plants (solar, wind, biomass, etc.) for the largest European renewable energy network operator, including examining the field IoT devices and their integration and network connections, aiming for automated PKI key management.
• Messaging with Kubernetes for large API-connected enterprise applications
• Risk and attack vector analysis, software quality & bug assessments
• Agile workload scheduling via Jira & Confluence
• Evaluation of pub/sub message streams for MQ and Kafka.
• Various tests with “best design approaches” for resilience patterns like circuit breaker designs, throughput measurement and monitoring, bulkhead governors – for robust EA design
• Integration of API management with IBM's API Connect to Kubernetes for platform-agnostic microservices API management designs. Google Apigee
• Solution health check approaches for load burst situations + remedy
• Research and evaluation of potential sub-service providers in the coordinating role as solution manager. CIS20 controls.
• DREAD and STRIDE security assessments.

• Design of a new cloud service
• Requirements Engineering
• API Design (REST API, Kafka)
• Consulting on architecture, feasibility and effort estimation
• Implementation of a microservice architecture
• Implementation of a Spring Boot web service
• Development of REST APIs including business and persistence logic
• Kafka consumers and producers
• Various Excel upload/download scenarios
• Change Data Capture
• Cloud provisioning with IaC/Terraform
• Go-live with 30,000 users
• Operation, support and bug fixing for other services

Environment/tools: GitLab, JIRA, Confluence, IntelliJ, Spring Boot, Java, Docker, Terraform, AWS ECS, Postgres, Apache Kafka, SAP Datasphere, JUnit, Debezium, Apache POI, Hibernate, JPA, Testcontainers

• Development of a microservice application for calculating postings on accounts

• Development of backend components with Java or JEE, Quarkus, Kafka, Rest API

• Development of the test component with mocking frameworks (Mockito)

• Development of integration test components

• Creation of OpenAPI specification format

• Configuration of CI/CD pipeline

• Development of frontend components with React

• Design, further development and optimization of system structures

• Code review

• Java Corretto 21, JEE, Quarkus, Golang

• Reactive programming with Spring WebFlux, Project Reactor

• Git, Azure DevOps for CI/CD pipeline, YAML, Json Swagger UI, Postman, Rest OpenAPI, Kafka Streams, Kafka Connect, Log4J

• Microservices, Jira, Confluence, MySQL, Docker, Kubernetes (deployment via Helm charts)

• Spring Security, OAuth 2, JWT, Sonarqube

• IntelliJ, Maven, logging framework Splunk, Agile method Scrum, Nexus, Vaadin V24, build tool Vite

• React, React.JS, Node.js, Jess/JavaScript, Tailwind CSS, Agile method Scrum, accessibility BITV, Playwright