CircleCI Experts in Germany

Further development of a software solution for managing audit applications and audit notifications according to §106d SGB V for the Association of Statutory Health Insurance Physicians in Hamburg.

• Developed numerous features, optimised performance, refactored code and analysed errors
• Refactored the development container setup
• Optimised the Gitlab-CI build pipeline
• Introduced improvements to the team workflow

• Translated complex operational requirements into scalable Salesforce configurations, automation flows and governance policies, ensuring clean and maintainable implementations
• Designed and optimised Flows to eliminate manual steps in key business processes, improving both performance and process compliance
• Managed user roles, permission sets and security settings for a multi-team Salesforce org; ensured data quality and system stability through structured governance practices
• Supported Marketing Cloud integrations and campaign automation workflows, collaborating with business teams on data-driven audience segmentation
• Coordinated release management and deployment activities with development teams, contributing to structured change control processes

• 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.

In my role as Senior Cloud DevOps Architect for BP, an oil and gas company, I had the mission to migrate the Electric Vehicle Charging platform of the EV Division from on-premises and Azure to AWS cloud, resulting in a hybrid multi-cloud, multi-tenant SaaS solution.

Deployment with Kubernetes for the application layer meant provisioning Kubernetes clusters managed by EKS and AKS, with a focus on integrating them into a multi-tenant environment. This integration was achieved by using Kubernetes namespaces and access controls to ensure data isolation and privacy enforcement.

In the database layer, we chose an RDS instance with PostgreSQL to support the backend infrastructure of our applications. Tenants shared the same RDS instance, but each had a dedicated schema.

To ingest near real-time data from physical charge points (CPOs), as IoT devices, via the OCPI protocol, we ran into significant delays with batch processing. As a result, we built a real-time streaming data pipeline using Apache Kafka, while prioritizing an event-driven architecture.

Led collaboration across multiple internal teams, external vendors, cloud providers, and on-site partners to integrate over five systems into a unified solution.

Achievements:

• Successfully designed and implemented hybrid multi-cloud solutions, integrating multiple cloud platforms (AWS, Azure) with on-premises infrastructure, using Site-to-Site VPNs, Firewalls, and Load Balancing.
• Led the migration of on-premises infrastructure to multi-cloud, multi-tenant infrastructure, resulting in 30% faster processing times.
• Migrated workloads from VMware and Hyper-V environments to cloud-based VMs, leveraging cloud-native services to optimize performance, cost efficiency, and scalability.
• Designed a multi-tenant Kubernetes platform leveraging the Kubernetes ecosystem, using Karpenter for dynamic EC2 node provisioning, KEDA for event-driven pod autoscaling (e.g., Kafka message lag), and Rancher for centralized monitoring of multiple clusters (EKS, AKS, or on-prem K8s), replacing Microsoft-centric Azure Arc management service.
• Designed and implemented Python-based FastAPI microservices as part of the EV core-backend on AWS EKS application layer, powering data ingestion and customer analytics pipelines.
• Developed asynchronous, event-driven APIs (Python-FastAPI) for real-time integration with CPOs, supporting OCPI 2.3 and OICP protocols.
• Designed and implemented a secure, production-grade Azure Databricks platform using Terraform, ensuring scalability and cost efficiency.
• Migrated on-premises ERP to a hybrid Dynamics 365 architecture with ERP hosted locally and CRM running in Azure, integrated via Azure Arc.
• Automated CI/CD pipelines for Databricks notebooks and jobs using GitHub Actions & Databricks CLI, reducing deployment time. Reduced infrastructure provisioning time by 70% by automating cloud resource deployment with GitOps.
• Ensured compliance with internal audit and data governance standards (GDPR) through OAuth2/OIDC-based authentication and fine-grained role-based access controls.
• Developed a Zero Trust security model, enforcing least-privilege access and microsegmentation, enhancing security posture and compliance with GDPR and NIST.
• Built interactive analytics dashboards in Amazon QuickSight, integrating data from S3 and Redshift to deliver real-time business insights and visualizations with embedded access for multi-tenant users.
• Led cloud security assessments and full-lifecycle cybersecurity integration during M&A, covering AWS, Azure, IAM (Entra ID), and data protection, while aligning security posture with NIST, ISO 27001, and GDPR across hybrid and cloud-native environments.
• Reduced cloud costs by 64% for a client's dev environment by implementing automated start/stop schedules for EC2 and RDS instances via AWS CDK with EventBridge Scheduler or AWS Systems Manager.

Tech stack:

• Infrastructure as Code: Terraform, AWS CDK, Ansible.
• Containers: Kubernetes on EKS, AKS, Docker.
• Streaming Data Processing: Kafka to Confluent Cloud, after AWS MSK.
• Frontend: TypeScript, React, NextJS, Hooks, Styled Components.
• Backend: Python with FastAPI, also Node.js with NestJS.
• Database: Aurora on PostgreSQL with TypeORM, RDS on SQL Server, Azure Databricks full setup and administration, ETL Pipelines.
• CI/CD and GitOps: GitHub Actions, Azure DevOps, ArgoCD.
• Monitoring and Observability: Prometheus and Grafana.
• Virtualization: Hyper-V, VMware Cloud on AWS, Azure Migrate.
• ERP Systems: Odoo, Microsoft Dynamics 365 Business Central on Azure, integrated with Azure Arc.
• Networking: Site-to-Site VPNs, AWS Direct Connect, Azure ExpressRoute, Firewalls (AWS Network Firewall, Azure Firewall).
• Security: IAM, NIST Framework, Zero Trust Security, AWS WAF, AWS Shield, GuardDuty.

• Drive migration of enterprise authorization platform from Styra DAS to open-source OPA via Skipper (Zalando's Golang-based ingress proxy) integration
• Optimise k8s resources and integrate native Prometheus metrics with OPA
• Migrate from internal monitoring solution to Prometheus CRs + Dash0

Tech Stack: Java/Kotlin, Golang, Python, Spring Boot, AWS, Kubernetes, Docker, OpenTofu, Prometheus, Grafana

Working as a full-stack (next.js, Postgres) engineer and consultant to build the core platform with underlying services for location-based comparisons and requests. I’m working on performance optimization across the stack (especially Postgres queries) and writing product specifications and the platform architecture with another colleague.

• Working on Telecommunication Apps on Android under NDA for the Military
• Participation in the development of backend services (Spring, Java)
• Android Development, Kotlin, Compose, REST, JSON, State-Machines, Android Studio, IP Communication, Cybersecurity, Agile

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

• RTE/Agile Coach for the introduction of SAFe 6 (Scaled Agile Framework)
• Establishment and implementation of a LACE (Lean-Agile Center of Excellence) for several ARTs
• Use of the tools: Azure DevOps with SCALE, Loop, MS Whiteboard
• Building the ART with 7 teams
• Training Product Owners, e.g. through SAFe POPM training and LearnSnacks
• Conducting the initial PI Planning as a Kickoff Planning Event
• Introduction of a demand process

• Consulted on IT security and process optimization, focusing on NIS2 and risk requirements
• Troubleshot and optimized plant core networks using STP, certified hardware, and open-source components such as OPNsense
• Redesigned network segmentation for VLAN rollout in a hybrid multisite multicloud setup using Tailscale VPN
• Facilitated cross-departmental discussions to align technical and social requirements
• Optimized monitoring with Grafana, Telegraf, and SNMP configurations
• Prototyped network setup for a new plant, including VLAN separation with Tailscale VPN
• Automated various scenarios using Python and Bash scripting

I implemented a Zero-Trust architecture for robust, military-grade maritime container mini data centers based on VMware & Tanzu to support containerized GIS workloads for ground forces. The main focus was on securing communications, workload protection, and data access in contested electronic battle environments affected by jamming, interception, signal manipulation, and constantly changing operational conditions. I designed and architected use cases so that every element of workload, identity, and system could continue to operate independently and securely even in degraded or disrupted scenarios. In parallel, I defined the enterprise and solution security architecture with LeanIX, Bizzdesign, and HOPEX as enterprise architecture, repository, and governance platforms to maintain architecture inventory, relationships, traceability, target pictures, and security governance in complex environments. For the architectural designs, I used Sparx Enterprise Architect to describe formal architecture views, interfaces, trust boundaries, and system architecture in both IT and OT environments. IriusRisk was used for threat modeling of the solution to identify architecture-driven risks, derive security requirements, and detect countermeasures and design gaps directly from the solution models. Risk and compliance management was supported with Archer. Architecture decisions, control gaps, and operational risks were translated into controlled governance and auditable compliance measures. For documentation, collaboration, and visual design, I used Confluence to maintain Architecture Decision Records, Security Blueprints, and workflows. I used Lucidchart and draw.io to create design artifacts tailored to stakeholders. I also defined OT security concepts with support from electrical and mechanical engineers in the areas of oil, vehicle onboard systems, rail, power plants, pharma, gas turbines, and nuclear technology. I created the end-to-end OT security strategy, starting with global policy, developed into standards and procedures, and finally aligned with Bell-LaPadula, Purdue Model, SABSA, TOGAF ADM, CENELEC 50701, IEC 62443, and NIST standards. In addition, I worked with engineering team leads to identify critical KBP assets and place them under protective measures that segmented SCADA, PLC, and HMI assets. I drove collaboration between Security, IT, and OT teams to create standardized workflows and use cases for the OT security solution catalog, while integrating Defense-in-Depth and Zero-Trust principles into operational environments. A key part of my work was integrating multidisciplinary engineering, security, and operations stakeholders into a unified security blueprinting strategy and ensuring that architecture, threat modeling, governance, and documentation were technically strong and operationally practical.

• Architecture and implementation of a fully digitalized closing flow for managing securities contracts within the DVAG infrastructure. The platform aims for maximum user-friendliness, modular extensibility and compliant handling of sensitive data.

• Implementation of a reactive UI structure with a focus on user guidance & accessibility.

• Dynamic control of form and closing processes including validation logic.

• Reactive state management via SignalStore (signals + selective effects).

• UX optimization through adaptive components and Playwright-based UI tests.

• Backend modularization to connect existing sales and contract logic.

• API stability and DTO design according to Clean Architecture principles.

• Collaboration with domain teams to define technical contracts and service boundaries.

• Management with GitHub.

• Unit tests with Jest, E2E tests with Playwright.

• Code reviews, CI-integrated test execution, iterative refactorings.

• Ensuring high coverage and UI stability in the closing flow.

• Technologies: Angular 18, RxJS, SignalStore, HTML5, SCSS, Spring Boot, Kotlin, REST, OAuth2, Jest, Playwright, Clean Architecture.

• Provide end-to-end software and architecture support to clients across finance, manufacturing, energy, and insurance sectors
• Collaborate with customers to understand complex business requirements and deliver scalable, future-proof solutions
• Design, implement, operate, and continuously improve software systems using modern technologies and cloud platforms
• Support the full solution lifecycle – from technical conception, system architecture, and development to deployment and operational readiness
• Act as a trusted technical advisor, bridging business and engineering teams to deliver high-impact solutions
• Lead architectural decisions with a focus on maintainability, cost-efficiency, security, and scalability across both cloud-native and on-premises environments

• AIX/Linux system administrator: deployment of LPARs (Logical Partitions) for SAP Kernel Development
• C/C++ SAP kernel development and integration to SAP HANA Database
• C/C++ programming and software integration, support for SAP kernel on AIX system; development and testing on SAP VDI
• Example: development of the ABEC Tool (AIX Build Environment Checker) to create SAP build environments for debugging process and benchmarking
• Benchmarking and test execution of SAP kernels (test from the communication to the SAP HANA Database and to SAP NetWeaver) on AIX
• Automate the SAP kernel build via Jenkins and benchmarking over crontab jobs
• New C/C++ compiler design and testing (based on Clang++ and LLVM)
• Customer ticket handling to resolve SAP kernel bugs and build failures
• SAP kernel development with Rust programming language, migrating some sub-kernel projects from C/C++ to Rust because of Rust's memory safety model, ownership system, and concurrency features
• Refactoring selected components in Rust and integrating them with existing C++ codebase via FFI