At HAUSGOLD, I've been instrumental in shaping the technical architecture and developer experience of the entire platform. My work spans from infrastructure to application development, with a focus on creating robust, scalable systems that enable the team to move fast without breaking things.

Key Achievements & Responsibilities:

• Infrastructure & DevOps: Designed and implemented the complete AWS cloud architecture, including containerization of all applications with Docker, streamlining project interactions with GNU Make, and establishing CI/CD workflows (migrating from Travis CI to GitHub Actions)
• Architecture & Standards: Introduced comprehensive documentation standards (YARD, Concept RFCs, Architecture Decision Records) and built a homogeneous API ecosystem using Ruby, Rails, and Grape, complete with an SDK (featuring an ActiveRecord-style API) ensuring interoperability between services
• Distributed Systems: Designed and operated a homogeneous Event/Message Bus using Apache Kafka, Apache Avro, and Confluent Schema Registry; built a Notification Distribution System supporting multiple sources and sinks (featuring Sidekiq and Karafka)
• Authorization & Security: Planned and developed a distributed RBAC authorization system using neo4j and Rust, including a high-performance neo4j HTTP client library for Ruby (Boltless); conducted security audits and implemented security features
• Platform Upgrades: Led major infrastructure modernization efforts including PostgreSQL (9.4 → 18), Redis/Valkey (3.2 → 8.1), Ruby (2.3 → 3.4), Rails (4.2 → 8.1), and migration from AWS Elasticsearch(5.5) to self-managed OpenSearch (3.5)
• Developer Experience: Developed isolated end-to-end test suites (Gherkin, Capybara, Chrome Headless/Xvfb), created a shared container image with comprehensive testing, and served as the first point of contact for technical support
• Business Intelligence: Deployed and operated Metabase and Apache Airflow; developed AI/ML solutions including hedonic property scoring with Python, FastAPI, and scikit-learn

As a Backend Engineer in the Express Booking team, I focused on developer productivity, infrastructure modernization, and system reliability.

Key Contributions:

• Containerized the Leipzig office infrastructure and built developer tools using GNU Make and Docker
• Introduced Git to the team, guiding migration from SVN
• Drove internationalization and localization of the Express Booking product
• Implemented automated build notification systems and introduced Rancher for container deployments
• Reorganized SSL/HTTPS certificate infrastructure
• Planned and deployed local office monitoring solutions

My work at trivago was characterized by taking ownership, making confident decisions, and actively sharing knowledge with colleagues. I was recognized for my capability and continuous learning.

I began my career at UNISTER (known for brands like ab-in-den-urlaub.de and fluege.de) as an apprentice and quickly advanced to lead development of mission-critical CRM systems for the email marketing division.

Major Projects:

• Led development of a Node.js and Pentaho PDI-based CRM system handling tens of millions of emails daily
• Built high-availability software systems with a focus on interfaces and Big Data processing
• Designed and optimized relational and non-relational database systems
• Evaluated and implemented techniques for asynchronous and parallel data processing
• Developed a generic tracking solution and a permission collection system for email marketing (GDPR compliance)
• Created the Greppy Framework, a top-layer framework built on Express.js with IPC and parallel processing capabilities

I was entrusted with extraordinarily demanding tasks due to my strong technical skills, quick grasp of complex situations, and ability to deliver high-quality results even under pressure.