CV

• 37 years old
• German
• Located around Munich
• Languages: German (native), English (fluent), French (enough for the last few holidays), some forgotten fragments of a few other languages
• Contact via e-mail

• Ability to find solutions for a problem, with or without help
• Communication in the needed amount, scope, channel, and to the right set of stakeholders
• Enthusiasm about many areas in IT and software development
• Considering, accepting and giving advice and help from/to my team members and colleagues
• I know my programming languages and tools – hence I can focus on finding solutions for project requirements instead of sitting over issues with the programming language.
• When working on a product, I want to be familiar with all parts. Typically I'm an allrounder for many areas, and a specialist in at least the components for which I have direct responsibility. Opening a code review means for me having tested the change locally, and being confident it will work in production. Large migrations are also not a problem, but only after preparing a detailed migration plan.
• Technical writing
• Keeping myself healthy

• Coding – a company should use me where I do best, and that is as engineer, not as manager. Engineers do a lot of programming, testing, understanding, troubleshooting, concise documentation, and supporting real applications in action.
• Responsibilities – working on 100 different construction sites is only fun until people burn out, and does not help or scale a company. The largest part of a job should be clear module/project responsibility and tasks.
• Interesting work – clearly, always having only boring and simple tasks would not be fun. I can be very enthusiastic about interesting technologies and projects.
• Atmosphere – nice and professional colleagues, preferably a healthy balance between regular work and frantic hurry-before-deadline work, integration of engineers' expert opinion into roadmap planning

• Go
• YAML 😏
• 🧠

• C++ (98-20)
• Python (2.7, 3.x)

• Bash
• Go
• Python
• Rust

• Kubernetes and related tooling (Helm, kustomize, Flux CD)
• AWS cloud products
• Linux and Docker
• Observability (Grafana)

• ZeroC Ice (framework similar to gRPC, but incl. orchestration)
• nginx and nginx-ingress
• FreeBSD and jails

• Ansible
• gRPC
• Terraform

• CockroachDB
• Hetzner cloud
• MinIO

• Managed Kubernetes and platform offering
• Cluster API (CAPI) and related infrastructure providers (e.g. Cluster API Provider AWS (CAPA)). Reviewer on the CAPA project since 2023-12, maintainer since 2024-07. Actively participating in their office hours and change discussions.
• Operators
• On-call duty
• Technical writing and documentation (SIG Docs)
• Explaining our platform offering at conferences

• Migrations, migrations, migrations (datacenter to cloud, traffic, payment method implementations, legacy to new systems, Brexit, bank switches)
• More advisory, knowledge transfer and training, less active operational involvement than before
• Handover of silo projects and knowledge
• Technical advisory for cross-company plans incl. RFCs for them

PPRO aims to be the payment industry partner of choice with a single platform offering for many international payment methods, acquiring services, along with certain value added services.

• Professional development in mostly C++ (using ZeroC Ice framework, later gRPC/Go) and Python (some central applications, scripts, and unit tests)
• Varying responsibilities, among which are these large topics: main processing gateway and staging environment, financial and technical reconciliation system, cloud migration (AWS/Kubernetes and CI/CD), incident handling
• Fully owning major topics and migrations
• Benchmarking and introduction of new processing gateway based on independent cells, replacing the previous monolithic infrastructure and deployment through a smooth and well-planned migration
• On-call rotation since 2020 with vast incident experience. Improvements to software and infrastructure observability and reliability.
• Helped develop the top 1 (by traffic) payment method integration and maintained it for years. PCI-DSS environment and audits, regular re-certification with the payment scheme, new major features, stability improvements. Also maintainer of the other top-tier payment methods.
• PCI-DSS induction and software security training for new developers, ownership of all PCI-related components
• Replaced old UI of payment gateway with modern, React and TypeScript based, heavily-used user interface (allowed linking to objects in the system, quick search, fine-grained search queries). One of the main tools for the daily job of Technical Operations, payment engineers and other departments.
• Became the go-to person (in many cases also owner, among others) for questions around the payment gateway and integrations, reconciliation system, and many other topics.
• Developed staging environment for payment gateway and main related processing systems, as close to production datacenters as possible (but in AWS EC2 and later EKS). As of 2022, it is still heavily used and maintained by developers after 4 years, and helped tremendously for implementing and testing risky changes in advance, and with confidence. I had also been main owner of the previous incarnation of the test environment (which was a single, local have-it-all VM per developer).
• Set up and maintained CI system for production FreeBSD packages. Used to check if builds work, and to provide packages to development environments such as the ones mentioned above. Created tooling so developers could easily spawn "compile hosts" using those packages in order to run fast, production-identical builds.
• Introduced external system for treasury and bank connectivity into our reconciliation system
• Maintained the high quality standards of the technical founder by means of code review, technical advisory, detailed and actionable migration planning
• Documentation
• Load testing, performance improvements, migration from single points of failure in datacenter to stateless, more reliable, automatically-deployed services in AWS/Kubernetes
• Handover and transparency for previously-"siloed" projects (I was the silo, but not deliberately)
• Several open source contributions for the company benefit (TLS SNI support in ZeroC Ice, terraform-inventory, Kubernetes tooling such as Helm and Skaffold, etc.)
• Took over technical ownership of wkv.com (voucher card sales) side business and preparation for ripout/sale to new owners (PHP / C++ code base for the web shop and administration interface)

Augmented reality company Metaio GmbH (purchased by Apple in 2015).

• Main work on the cross-platform Metaio SDK, the base framework of the company's augmented reality technology.
• Development for Android, iOS, Windows, OS X, the Unity 3D plugin on the same platforms, and the JavaScript API AREL.
• Using all of these: C++, Objective-C(++), Java+SWIG, JavaScript, C#, GLSL (ES), Python.
• Support for customers (helpdesk, e-mail, direct contact) and internal developers.
• Module and project responsibility for several parts of related products, e.g. Metaio Toolbox which included calibration and 2D/3D tracking tools.
• Notable achievement: Interactive camera calibration tool for Epson Moverio BT-200 smart glasses by human-friendly capture of 3D-3D correspondences.

• cluster-api (CAPI) and cluster-api-provider-aws (CAPA) (I'm a regular contributor and reviewer), both part of Kubernetes SIG Lifecycle
• hobby-kube heavy personal user and co-maintainer
• Skaffold, the central tool for building container images, testing them, running on Kubernetes, and integrating developer workflows closely with CI/CD
• Other Kubernetes-related projects. See my contribcard.dev entry or GitHub profile.

• kiss-templates, generic C++ text templates made easy (port)
• hieroglyph, a Sphinx extension for building slideshows from documentation (port)
• Howard Hinnant's C++1x date library (port)
• ZeroC Ice (not the maintainer, but actively testing and submitting bugfixes and updates; port)
• OWASP Dependency-Check, a "utility that identifies project dependencies and checks if there are any known, publicly disclosed, vulnerabilities". It can create reports in various formats and is easily pluggable into CI either by specific plugins (for Maven/Jenkins) or the command line program (port)

Master’s Thesis in corporation with the chair for applied software engineering at Technical University of Munich. During most of the time writing the thesis, I've been living in Co. Cork, Ireland for personal reasons.

Comparison and evaluation of cross-platform frameworks for the development of mobile business applications (link to blog post with PDF download)

Work as software engineer for startup Walnuss LLC to develop a next generation, RFID-based ordering system from the ground up, also tasks as system administrator (e.g. VServer, OpenVPN, firewall administration). Software was in C#.

M.Sc. Informatics studies at Technical University of Munich (Technische Universität München, TUM). Overall grade 1.3 (German grade).

Dual study B.Sc. Applied Computer Science at the University of Cooperative Education in Stuttgart (DHBW Stuttgart) with internship phases at Hewlett-Packard, Böblingen. See internships listed below. Overall grade 1.4 (German grade).

01/2010 – 02/2010, 05/2010 – 08/2010

Bachelor’s Thesis project (development of a distributed deployment system as extension to the previous HP Labs project).

06/2009 – 09/2009

Work on the “Trusted Virtualized Client” project at HP Labs, Bristol, United Kingdom (details confidential; keywords: Xen hypervisor, TPM, early cloud computing).

12/2008 – 03/2009

Development of two business VBA applications for the department “PSG Consumer Category” in order to streamline offer and sales processes, including technical documentation, patching of existing application for Microsoft Office version compatibility.

03/2008 – 05/2008

Migration of an internal web application from a HP-UX to a Linux server, bug fixing and further development of the application, development of a complete backup and monitoring web interface for the server (using PHP and MySQL backup mechanisms), documentation of the server setup.

Alternative service at a retirement home

Graduated with Abitur degree. Overall grade 1.8 (German grade).