About Me

I am a Freelance Software Developer and Infrastructure specialist with a strong background in system administration and software development. Having experienced the shift from operating infrastructure in on‑site data centers towards cloud based offerings, helps me to pick the right technologies for the problem at hand. I have written operated and maintained software in a broad range of languages and technologies.

I enjoy designing simple scalable systems that can easily be adapted to changing requirements. I regularly operate services and third party applications 24/7 on premise and in the cloud. Due to my experience in system operation

I design software with a strong focus on long term maintainability and ease of operation. I strongly believe in test‑first methodologies and continuous delivery to create short and valuable feedback cycles. I love taming the complexity of distributed systems with a big emphasis on creating a smooth developer experience. Security is an integral and continuous part of my software development and operations approach.

Ecosystems

Java (Spring Boot, Dropwizard), Kotlin, Bash Python, JavaScript, PHP, Go, JavaScript, Typescript

Technologies

Linux, Kubernetes, K3S, Ansible, Salt, Terraform/ToFu, git, subversion, HiveMQ, VerneMQ, Helm, Consul, Vault, Nomad, Docker, Vagrant, Kibana, Grafana, ELK, GoCD, Jenkins, TeamCity Gitlab, Github Actions, Concourse, PostgreSQL, Mysql, MariaDB, Keycloak, DataDog

Networking & Protocols

TCP/IP, DNS, DHCP, CanOpen, MQTT, Cisco, TLS, OpenVPN, IpSec, Nagios/Zabbix/OpenNMS

Clouds

AWS, Azure, Hetzner, GCP

Methodologies

Test Driven Development, Continuous Delivery/Integration, Pair Programming, Kanban, Model Driven Development, UML, SCRUM, DevOps, Infrastructure as Code, Clean Code

Project History

Hetzner infrastructure

  • Initial assessment and planing of cloud implementation
  • Implement and test disaster recovery processes
  • Development of ansible roles and developer tooling
  • Migration of databases to Hetzner cloud servers

Migration from Google Cloud to Hetzner

  • Initial assessment and planing of cloud migration
  • Capacity planing and testing
  • Planing and implementation of a cloud‑agnostic Kubernetes cloud platform on Hetzner cloud
  • Technology workshops and knowledge transfer for Kubernetes and Helm
  • Implement and test disaster recovery processes
  • Migration of databases to dedicated Hetzner server database cluster

Cloud migration AWS to Azure

  • Initial assessment and technical workshops for cloud migration requirements and planing
  • Planing and implementation of cloud-agnostic Kubernetes cloud platform components
  • Technology workshops and knowledge transfer for Kubernetes and helm
  • Evaluation and introduction of infrastructure tests
  • Assessment and advisory for IDM solutions
  • Live migration of VerneMQ MQTT broker cluster

Maintenance and operation of IoT Platform for Connected Machines

  • Feature development and day-to-day platform operations including on-call duties
  • Drive technical evolution of the IoT platform
  • Ensure technical alignment with internal and external parties
  • Mentoring and development of graduates
  • Evaluation of new technologies
  • Technical integration into the company IT landscape
  • Ensure and oversee secure and stable operations

Implement Keycloak IDM solution

  • Replace custom built IDM with Keycloak}
  • Extend Keycloak with custom Salesforce backed user provider}
  • Implement production ready deployment and monitoring}
  • Periodic security assessment and threat modelling}
  • React and resolve production incidents}

Rollout Infrastructure for Covid19 Portal (non-EU)

  • Evaluation of hosting provider
  • Implementation of Ansible roles
  • Disaster recovery and security firedrills
  • Documentation and handover of operations

Extending billing platform and SAP integration

  • Overhaul billing process for Cloud products
  • Replace manual billing process with automated SAP data export
  • Load testing and sizing evaluation
  • Implement and extend monitoring for billing process KPIs
  • Migration of billing data from TimescaleDB to Elasticsearch
  • Stabilization of data retrival and report generation

Building a custom Multi-Cloud Frontend for OpenStack and Kubernetes

  • Story refinement with Stakeholders
  • Evaluation of technical solutions
  • Feature development
  • Code reviews
  • Level 3 operational support and bugfixing
  • Build and test process optimizations

Let’s work together

If you are looking for a freelance software Developer or infrastructure specialist, give me a call or write me an E-Mail.