macOS Experts in Berlin

• Codebase Evaluation & Problem Design: Designed and stress-tested complex software engineering problems against large open-source Python codebases (including pandas), requiring deep context acquisition and architectural understanding to produce well-scoped, realistic problem statements aligned to strict correctness guidelines.
• Agent Failure Analysis: Assessed LLM coding agent solutions for correctness and completeness, identifying meaningful failures across edge case handling, dtype behaviour, and multi-column NaN propagation logic; documented findings with precision for downstream evaluation use.
• Programmatic Test Suite Development: Authored comprehensive pytest suites to programmatically verify agent-generated solutions against defined requirements, with deliberate coverage of boundary conditions and failure modes not caught by naive implementations.
• Containerised Environment Engineering: Built and debugged Docker environments for reproducible agent execution, including git-based repository provisioning, dependency pinning with npm ci, and multi-stage Dockerfile authoring across Linux-based containers.

• Acted as technical consultant to optimize multi-layer ensemble models combining ResNet, CNN-BiGRU-Attention, and XGBoost.
• Guided implementation of a Logistic Regression meta-learner to solve class imbalance problems, achieving 92.86% accuracy and 0.9644 AUC on PTB-XL and Chapman-Shaoxing datasets.

• Work within time-critical operating procedures; coordinate issues with customers, partners and central support.
• Maintain reliable handovers and concise incident communication when service, equipment or routing issues occur.

• Mobile Device Management (MDM) for iOS devices (iPads, iPhones)
• Management, configuration and rollout of policies, apps and security measures
• eSIM setup & management as well as management of mobile plans and contracts
• User management (create, block, delete) in the SecurePIM security solution
• Device registration, preparation and setup of devices with Windows 10/11 and peripherals
• 1st & 2nd level support and handling of IT requests via the ticket system
• Troubleshooting, fault isolation and repair of devices
• Creating and maintaining guides, training new users and handling user questions

• Built the Peax Berlin team
• Candidate selection and interviews
• Hiring in coordination with the Recruitment Manager
• Coaching and mentoring to develop team members and the team
• Technical and disciplinary leadership of team members
• Acquired new key clients and expanded existing accounts
• Sales and business development
• Ongoing staff development
• Acted as information link between the team and Recruitment Manager, including reporting
• Supported brand growth in collaboration with marketing (online & offline)
• Participated in trade shows and events
• Defined and enforced standards
• Developed new services in cooperation with company management
• Revenue responsibility and ensured profitability
• Budget management
• Daily operational tasks as a recruiting consultant
• Built a talent pool and client portfolio in strategic target markets

• Establishing Identity & Directory Management as a new (split-off) team & product within the IAM cluster.
• Leading the “Identity & Directory Management” product (8 people) as Product Owner.
• Concept for ‘Digital Identities’, i.e. IDs with n users/accounts and strategy for a modernized product offering.
• Upgrading APIs, migrating to a containerized infrastructure, rolling out international markets & standardized solutions across the REWE enterprise group.
• Tech: OpenText™ (NetIQ) eDirectory & Identity Manager, LDAP, SAP HR/HCM, Docker/Kubernetes/Podman, REST APIs, Microsoft Active Directory & Entra ID, postgresDB, Keycloak, Ansible, Cyberark (PAM), Apache Kafka, Jira, Confluence, Miro.

• Projects for federal networks (NdB).
• CR management, EoL change requests, design and documentation according to ITSCM.
• Data center planning.
• Project management and engineering subproject management.
• Software development for virtual server environments according to BSI.

• Built a successful sole proprietorship connecting German companies with specialized HR and recruiting freelancers and managed all business operations
• Established a network of over 1,000 freelancers and led a team of up to three independent contractors to ensure excellent results
• Developed and implemented tailored solutions to support companies in scaling their teams quickly and efficiently

• Vram.run: Rust, TypeScript, HF Inference API with 19 providers, 220+ HW configs, and 30+ cloud GPUs. Search a model to see which API providers serve it, which GPUs can run it locally (and how fast), and what cloud rental would cost. Or search your hardware and see what fits. Also includes a Rust CLI.
• Psychotron: JavaScript, Web Audio API, AudioWorklet, Canvas 2D. Front-end for flash fiction audiobook with Web Audio DSP chain featuring pitch-shifting, 12-voice chorus, flanger, 13-band EQ, and convolver reverb. Includes a 2D canvas effect morphing engine and synchronized teleprompter.
• RecentWork: Swift, macOS, FSEvents, launchd. macOS daemon that watches project directories and maintains a flat folder of symlinks to recently modified files. Homebrew installable.
• Mini-llm: Bash, macOS, launchd, Ollama, llama.cpp, MLX, Open WebUI. Single command that turns a Mac Mini into a headless AI server.
• ThatSlop: JavaScript. Chrome/Firefox extension for AI content detection on LinkedIn and Twitter.
• Smux: Bash, tmux. Human-friendly tmux wrapper that is Homebrew installable.
• Learn Rust Course: Rust. Course on Rust’s memory model for C++ programmers, written from experience of transitioning from C++ to Rust at Irreducible.

For Regiolux GmbH, I produced several brochures and an info sheet in seven different languages in this project. To make offset printing especially efficient and cost-effective, I implemented all language variants in Adobe InDesign on separate layers. This way, the different versions could be produced by simply swapping the black printing plate—a simple but effective solution.

In addition to working according to the corporate design, my tasks also included final artwork and creating web and print PDFs. I coordinated communication with translation agencies and printers, ensuring a smooth project flow.

• Sorting of customer orders
• Packaging and warehouse assistance
• Working late nights and weekends (130 hours/month)

• Supported national site migration & the software team
• Installed printers, scanners, network cabinets, antennas, etc.
• Prepared and assigned hardware
• End-user support, administrative & production migrations, stakeholder management
• Ensured workstations were operational
• Configured printers and phased out outdated devices

• Quality assurance of the "Telematics Infrastructure Messenger (TI-M)" application
• Introduction of test management for the TI-M product
• Reviewing test requirements (gematik specification)
• Creating test documentation
• Defining different test levels
• Designing test scenarios in coordination with subject matter experts
• Test data management
• Responsible for test case specification from user stories
• Responsible for performing manual tests on various platforms (iOS & Android)
• Conducting release and integration tests
• Bug analysis and documentation
• Retesting bugs
• Skills: test management documentation, requirements analysis, frontend testing, mobile testing, Jira (TestFLO), Confluence, agile processes, Telematics Infrastructure Messenger, accessibility