DevOps Engineering & Software Development

2/2019 – 12/2019

• Deployment automation to OpenShift with Jenkins and Helm
• Development of cross-cutting application components (e.g. authentication, logging, etc.) in Java
• Development of microservices
• General system architecture consulting
• Performance engineering

Amazon Web Services (AWS), Elasticsearch, Java (allg.), Jenkins, Kubernetes, Openshift, Spring Framework

8/2018 – 12/2021

• Setup of Kubernetes clusters in AWS and integration with AWS services (ELB, Route53, IAM, etc.)
• Administration of Confluent Kafka and RabbitMQ
• Occasional development of microservices (Java)
• Containerization of microservices
• Setup of a cluster monitoring solution, based on Prometheus
• Setup of log aggregation (EFK stack)
• VPC design and automated provisioning with terraform
• Secret and certificate management
• CD pipeline enhancements to accommodate new deployment model
• Design and implementation of a data pipeline for image processing
• AWS lambda development (Python)
• Design and implementation of a multi-region Kubernetes cluster
• Design and implementation of a GitOps based CD pipeline
• Implementation of AWS WAF

Amazon Web Services (AWS), Bash Shell, Docker, Elasticsearch, Firewalls, Golang, Apache Kafka, Continuous Integration, Kubernetes, Postgresql, Python, Server-Monitoring

11/2017 – 8/2018

• Software architecture consulting
• Architecture reviews to ensure adherence to Schufa IT standards
• Design and code reviews
• Deployment automation (CI/CD)

Java (allg.), Jenkins, Software Architecture, Spring Framework

9/2017 – 8/2018

• Design and development of complex CD Pipelines
• Kafka cluster installation and administration
• OpenShift (Kubernetes) administration
• Dockerization of applications
• Infrastructure automation

Ansible, Apache Maven, Confluence, Docker, Java (allg.), Jenkins, Jira, Apache Kafka, Continuous Integration, Kubernetes, Openshift, Postgresql, Python, Red Hat Enterprise Linux (RHEL), Scrum, Spring Framework, Test Automation

7/2016 – 9/2017

• VPC design and implementation
• Implementation of a fully automated installation of a production grade Kubernetes cluster in AWS, based on Ansible, Packer and Terraform
• Integration of Kubernetes with AWS autoscaling
• Installation of a logging solution for Kubernetes, based on the EFK stack
• Installation of a monitoring solution for Kubernetes, based on Instana
• Kubernetes administration, including definition of various Kubernetes primitives
• Automation of infrastructure provisioning (Terraform, Packer, Ansible)
• Automated configuration of various AWS resources, including RDS, Elastic Search Service and Elasticache
• Development of deployment pipelines
• Setup of an external caching layer
• Configuration of SSL/TLS
• Migration of multiple existing applications to the target platform (Docker/Kubernetes)
• Involvement in Ops activities according to DevOps principles

Amazon Web Services (AWS), Ansible, Bash Shell, Confluence, Docker, Elasticsearch, Java (allg.), JavaScript, Jira, Continuous Integration, Kubernetes, Linux Entwicklung, Spring Framework

5/2013 – 6/2016

• Design of the application architecture
• Selection of technologies
• Design and implementation of critical components, e.g. an audit logging solution
• Design and implementation of system integrations
• Implementation of custom data migrations (ETL) for existing systems to be replaced, applying functional programming paradigms (Clojure)

AngularJS, Docker, Git, Hibernate (Framework), IBM WebSphere Application Server (WAS), Java (allg.), JavaScript, Jenkins, Oracle Database, Spring Framework, Ibm Websphere Mq

5/2012 – 4/2013

• Design of a reference architecture for a global, harmonized/centralized eBusiness platform. The main goal was to enable support of varying requirements of different countries / regions and to enable efficient development with highly distributed teams.
• Elicitation of architectural requirements
• Collaboration with stakeholders at different levels
• Development of an Architectural Spike

AngularJS, Confluence, Enterprise Architect (EA), Java (allg.), Jira, Spring Framework, UML

6/2009 – 2/2012

• Design of application and integration architecture
• Requirements engineering
• Technical leadership of distributed development team
• Development of application and integration components

Hibernate (Framework), IBM WebSphere Application Server (WAS), Java (allg.), Wildfly, Oracle Database, Spring Framework, UML, Ibm Websphere Mq

8/2008 – 6/2009

• Extension of existing eBusiness application suite and comprehensive modernization
• Refactoring of existing code base
• Replacement of EJB 2.x persistence layer by JPA / Hibernate
• Redesign of service layer

Enterprise Architect (EA), Hibernate (Framework), Netview, IBM WebSphere Application Server (WAS), J2EE, UML, WebSphere Enterprise Service Bus (ESB), Ibm Websphere Mq

1/2008 – 12/2008

• Design and implementation of web service layer
• Development of web service design guidelines
• Evaluation of web service security technologies

Enterprise Architect (EA), Netview, IBM WebSphere Application Server (WAS), J2EE, UML, XML

1/2008 – 7/2008

• Redesign of application frontend
• Assess impact of frontend migration
• Migration of frontend to JSF

Enterprise Architect (EA), Informix, J2EE, Javaserver Faces, Solaris, UML, WebSphere

1/2006 – 12/2007

• Design of application architecture
• Integration of 3rd party products with portal platform
• Design and implementation of portlets

Enterprise Architect (EA), J2EE, Javaserver Faces, Lotus Notes Domino Server, Oracle Database, UML, WebSphere

4/2004 – 12/2006

• Development of ETL processes
• Database design
• Development of reports

Microstrategy, Oracle Business Intelligence (BI), Oracle Database, Perl

3/2003 – 1/2004

• Development of frontend and backend components
• Database design

IBM DB2, Enterprise Javabeans, IBM WebSphere Application Server (WAS), J2EE, Ibm Websphere Mq, XML

1/2001 – 3/2003

• Development of a web application framework using Java servlet technologies
• Development of middleware components based on EJBs
• Development of a messaging framework based on JMS

J2EE, Java Message Service, Java Database Connectivity, UNIX, Ibm Websphere Mq, XML