Freelancer in Hamburg

Waldemar Kornewald

Hi, I'm Waldemar Kornewald - a freelance software engineer based in Hamburg, Germany. I've been writing software since my early childhood (1996) and constantly improving my skills in designing easy to understand, maintainable code.

I'm available on-site in Hamburg or remote for:

  • Mobile apps: Android, Flutter, Kotlin, Java
  • Frontend: React, TypeScript, JavaScript
  • Backend: Python, Django, Flask
  • DevOps: Kubernetes, Docker, infrastructure-as-code
  • Architecture consulting

If you need help with one of your projects just contact me:


2020 – nowIBM: Android/Kotlin lead developer for IBM's electronic health record, security admission (gematik), end-to-end encryption, architecture
2017 – 2020Ovy: Flutter, Android/Kotlin/Java, Flask/Python, Bluetooth LE (custom thermometer), Dockerized dev env, Google App Engine, Redis
2017 – 2017SPIEGEL: Kubernetes setup/ops (on-prem & GKE), how-to-use workshops, Elasticsearch, PostgreSQL, Prometheus, Kibana, Grafana, Docker images for various services, etc.
2014 – 2020Locandis: Android/Kotlin/Java, React/TypeScript/JavaScript, Django/Python, Bluetooth LE (iBeacons), PostgreSQL, Redis, Docker
2015 – 2018sefibo: React/TypeScript/JavaScript, Django/Python, Elasticsearch, PostgreSQL, Redis, Docker, custom task queue
2014 – 2015Mainmetrics: Django/Python/SQLAlchemy, Python/JavaScript frontend, PostgreSQL, Redis, Docker
2008 – 2014various customers: Python, JavaScript, Django, Android, Java, Google App Engine, PostgreSQL, MySQL, Elasticsearch, MongoDB, Redis, C++
1999 – 2008various open-source projects: Python, Django, Trac, C++, Java, GPIB, WinAPI, Perl, PHP, x86 asm, USB HID


Over the past 20 years I've also made several open-source contributions: