About me

I'm Jens Dieskau, a software developer, infrastructure operator, tinkerer, and wannabe designer from Germany. Before I do a handshake three times, no matter how easy and fast it is, I prefer to automate it right away. I am not afraid of new technologies and challenges. My home is the shell. My tools are ssh, vim, tmux & co. Code that is not in a git repository does not exist for me. I love and live open source software and there is hardly any technology I have not looked at already at least once. Besides programming, I have in-depth knowledge in areas like virtualization, networking (LAN & SAN) and in operating server applications of all kinds.

Work Experience
2021 – Today IT Architect
Volkswagen AG		 Volkswagen AG
  • Planning and implementation of a migration of an existing on-premise IT landscape to AWS
  • End to end deployment automation built with Terraform and Ansible
  • Design and implementation of a backup and disaster recovery solution based on AWS Backup API and boto3 (Python)
2017 – 2021 DevOps Architect
SAP UCC Magdeburg		 SAP UCC Magdeburg
  • Data center transformation from VMware towards libvirt/KVM (Infrastructure as code)
  • Development and maintenance of a reverse proxy server for access to SAP systems (CPI-C, RFC w/ Saprouter), database and application sever (HTTPS w/ NGINX)
  • Building a backup solution based on SEP Sesam and HPE Storeonce
  • Automatic certificate management for SAP systems
  • Best practice development and training of staff in using of Git, Python and JavaScript
2014 – 2017 DevOps Engineer
SAP UCC Magdeburg		 SAP UCC Magdeburg
  • Data center transformation from HP-UX cluster with ≈400 SAP Netweaver and HANA instances towards VMware with Linux VMs
  • Responsive mobile app development (native Android + SAP UI5)
2010 – 2014 Scientific Assistant
SAP UCC Magdeburg		 SAP UCC Magdeburg
  • Migration of Perl scripts from HP-UX to Linux
  • Data center monitoring
  • Administrative tasks in end user office environment
2012 – 2013 Scientific Assistant
Technische Hochschule Brandenburg		 Technische Hochschule Brandenburg
  • Development and evaluation of pattern recognition techniques for identification and classification of fingerprint images
  • Evaluation and implementation of machine learning algorithms
  • Porting Python and Java projects to C#
Freelance
2019 In4MD Service GmbH
  • Consulting and development of a crypto concept for an ISO/IEC 27001 certification
2018 – 2019 Westfälische Wilhelms-Universität Münster
  • Front-end testing of several SAP UI5 applications based on Selenium (Grid)
  • Focus on parallelized testing to simulate the use of hundreds of students
  • Development of a framework for easy handling of new test cases
  • Employee training
2017 – 2018 Berufsakademie Sachsen / Dr. Pape & Co. Consulting GmbH
  • SAP UI5 mobile app development („Direktoren-App“)
  • End users are the directors of the „Berufsakademie Sachsen“
  • The application displays clearly information of faculty, students, curricula, room bookings, and enrollment and disenrollment data
  • Creation of necessary OData services
Selected Projects
2021 – 2022 Migration to AWS

4 person team, 1 year, 90000 user,

The main task was to migrate an existing IT landscape from an on-premise solution to AWS. Neither functionality nor performance had to be affected in the process. The roughly 90000 users of the hosted systems should not notice any platform change. The focus was the end-to-end automation of the entire landscape, from infrastructure components up to the application level. A new backup concept and a disaster recovery plan also had to be completely redesigned.

Tags: AWS, Terraform, Ansible
2018 – 2020 Migration of a VMware environment to libvirt

3 person team, 2 years, >400 customers, ≈600 VMs, 8 hosts

The goal of the project was to migrate a VMware landscape to libvirt (KVM). Features such as VM (live) migration, snapshots, hotplug memory, CPU and hard disk extensions must still be possible in the new landscape. Additionally, the focus lied on a complete automated deployment process: From VM provisioning to automatic application installation.
After evaluating a wide variety of complete systems from different companies and open source solutions, it was decided that an in-house development based on the automation software Salt should be carried out.

Tags: SaltStack, libvirt, Multipath SAN, VxLAN
2014 – 2015 Project „AccessCluster“

One-Man-Show, 1 year

Development of a central access point for different application servers from different customers. Before the changeover, each system had its own public IPv4 address. This was costly and difficult to secure in the long run.
The challenge here was to find a suitable reverse proxy solution for the different protocols and to configure it fully automatically.

Tags: SAProuter, NGINX, Firewall, NAT
2014 – 2015 HPUX/Itanium superseded

4 person team, 1 year

Replacement of a legacy HP-UX environment with a fully virtualized VMware landscape.

Tags: HP-UX, VMware, NSX