Backend Developer
Java in production. Go by choice. // Berlin, Germany
Backend developer based in Berlin, currently lead developer of Q.Daba platform at ETC Solutions — a quality measurement and reporting platform used by the Swiss Federal Office of Transport and major transport operators across Switzerland and Germany.
Professionally I work with Java and relational databases at scale. Outside work I build almost everything in Go.
ETC Solutions GmbH — Apr 2025 — Present
Leading development of Q.Daba, a public-transport quality measurement platform used by the Swiss Federal Office of Transport and transport operators across Switzerland and Germany.
HTW Berlin - ETC Solutions GmbH — Dec 2024 — Feb 2025
"Performance Comparison of DuckDB and ClickHouse with Respect to a PostgreSQL Solution on Large Mobility Datasets" — benchmarking and optimizing analytical databases for high-volume transport data.
ETC Solutions GmbH — Apr 2024 — Nov 2024
Implemented customer-driven changes, fixed bugs, and improved system functionality.
Standardized the DatNet database structure using Liquibase, ensuring seamless operations and scalability.
ETC Solutions GmbH — Nov 2023 — Mar 2024
Unified and optimized Q.Daba database structures for diverse customer implementations using Liquibase.
HTW Berlin — University of Applied Sciences — Apr 2021 — May 2025
HTW Berlin — ETC Solutions GmbH — Dec 2024 — Feb 2025
"Performance Comparison of DuckDB and ClickHouse with Respect to a PostgreSQL Solution on Large Mobility Datasets"
# side projects
Multipage website for a dental clinic in Santiago, Chile. NextJS, TypeScript and TailwindCSS with Google Maps and live Google Reviews integration. Deployed on Vercel with automated CI/CD, SEO and analytics.
Portfolio website for a fine artist. Go, Templ and TailwindCSS, deployed on Fly.io with an automated Nix + Docker CI/CD pipeline. Fast and dependency-light.
Pomodoro timer daemon for Waybar. JSON output to stdout, controlled over a Unix socket IPC from keybinds or scripts, persistent state across restarts, relay mode for multiple consumers.
magit-style git TUI written with BubbleTea. Stage files or individual hunks, expand/collapse diffs, commit — the magit workflow without Emacs.
Flat-hunting assistant for Berlin's WG market: Selenium scrapes wg-gesucht listings, structural filters narrow them against user preferences stored in MongoDB, GPT does deep filtering and drafts a personalized application text — delivered via a Telegram bot.
RAG chatbot over uploaded PDFs: FastAPI backend chunks documents with LangChain, embeds them into ChromaDB, and answers questions via OpenAI strictly from document content. React frontend, deployed with Docker Compose or Kubernetes.
LSTM networks for daily stock price prediction (OHLCV) on 20 years of GOOGL data. Four documented experiments — baseline LSTM, independent volume scaling, multi-input LSTM, bidirectional LSTM with attention — comparing architectures by test MSE.
Bachelor thesis benchmark suite: DuckDB and ClickHouse vs. a PostgreSQL baseline on large public-transport mobility datasets. Punctuality and hourly-aggregation workloads per SQL dialect, with per-second CPU/memory/disk profiling and federated-access variants.
Multiplayer German card game (Uno-style) for up to four players with virtual opponents. Component-based architecture: game engine, rules, persistence, player management as independent Maven modules.
My first project (2022): recipe search by ingredients or name, with favorites. Spring Boot REST backend with JPA on PostgreSQL, Gradle build, CI pipeline — where it all started.
[languages]
[backend]
[databases]
[web]
[tooling]
[spoken]