Profilbild von Stefan Steinert IT Engineer aus Heidelberg

Stefan Steinert

verfügbar

Letztes Update: 01.01.2024

IT Engineer

Abschluss: Dipl.-Informatiker (FH)
Stunden-/Tagessatz: anzeigen
Sprachkenntnisse: deutsch (Muttersprache) | englisch (verhandlungssicher)

Skills

  • Key Areas
    • Linux-related middleware, container- and cloud-stacks, devops, tailored processes, automation
    • Software-architecture and -development
    • Network planning and security
  • Operating Systems
    • Linux expert, esp. RedHat/Fedora/CentOS and Debian/Ubuntu. Also numerous other derivates like NixOS and MirageOS. Mastering a wide range of standard Linux services, e.g. cgroups, systemd, sshd, bind, dhcpd, iptables/netfilter, rsyslog, syslogng, snmpd, auditd, smbd, postfix, squid, openvpn, redis, tor, ...
    • MacOS, IOS
    • AIX
    • embedded systems / soc e.g. raspberry, vocore, arduino, esp32, esp8266
  • (Programming) languages, including:
    • Python/Jython
    • Unix Shell
    • Java, Java EE
    • Go
    • XML/XSD/XSLT
    • yaml/json
    • C, C++
  • Cloud systems and tooling, including:
    • OpenTelekomCloud/OpenStack (and cli tools)
    • GCP, GKE (and cli tools)
    • AWS (and cli tools)
    • terraform
    • puppet
    • ansible
    • cloud-init
    • packer
  • Middleware and supporting systems, including:
    • Kubernetes (k8s)
    • WebSphere
    • Geronimo / WebSphere CE / Liberty profile
    • JBoss
    • Oracle WebLogic
    • Nginx
    • Apache
    • Tomcat
    • GitLab
    • Jenkins
    • Prometheus/Grafana
    • haproxy
    • Confluence
    • Jira
    • BitBucket
    • Artifactory
    • Bugzilla
    • ...
  • Development environments and tools, including
    • Microsoft VS-Code
    • IntelliJ, Eclipse
    • Distributed development (Unix/Windows)
    • git, svn, cvs
    • ant, maven
    • docker
    • vagrant
    • npm
    • pip
    • gem
  • Relational databases
    • PostgreSQL
    • MySQL
    • Oracle
    • DB2
    • Microsoft SQL Server

Projekthistorie

06/2022 - 11/2022
ONCITE Open Edition
German Edge Cloud (Internet und Informationstechnologie, 250-500 Mitarbeiter)

Contribute to the codebase for automated installation of ONCITE Edge Clouds, a Kubernetes and OpenStack-based on premise mini data center. Review and supplement Prometheus-based monitoring and alerting. Design and implement connectivity to monitor Cumulus switches and Junos firewalls in the separated management network.


07/2021 - 06/2022
Operationcenter Observability
German Edge Cloud (GEC) (Internet und Informationstechnologie, 250-500 Mitarbeiter)

Design and implementation of an overall observability solution for monitoring and visualization of GEC customer infrastructure. Design and implementation of a controller/agent solution for automatic provisioning and deployment of customer systems (golang, REST, ORM, Dependency Injection). Evaluate and build centralized metrics and logging infrastructure (Prometheus, Loki, Victoria Metrics, Promtail) on Kubernetes (k3s, k3d, Rancher).


01/2021 - 07/2021
Unicorn HEC Automation
SAP (Internet und Informationstechnologie, >10.000 Mitarbeiter)

Design and develop multi-tenant, multi-cloud IPsec VPN concept based on SUSE Linux, Strongswan and Free Range Routing (FRR). Evaluate alternatives regarding manageability and performance. Design and implement zero-downtime failover concept with automatic route redistribution using BGP. Build automation code using Github workflows, Terraform Enterprise (TFE) and ansible/AWX.


01/2019 - 09/2020
Distributed Splunk platform on OTC
T-Systems Switzerland (Internet und Informationstechnologie, 250-500 Mitarbeiter)

Setup multi-tenant, multi-stage Open Telekom Cloud (OTC) infrastructure using terraform and openstack. Design and implement dynamic provisioning concept using puppet and ansible. Iteratively carve out multi-developer gitops-style workflows. Implement and proof Splunk HA multisite setup. Design and implement comprehensive platform monitoring using Prometheus/Grafana as well as Splunk ITSI.


11/2018 - 12/2018
Linux Auditing
T-Systems Switzerland (Internet und Informationstechnologie)

Establish concept for manageable global auditing using Puppet, optimize auditing rules for scale, create central rsyslog receiver and attach it to Splunk, setup and tune Splunk app


10/2018 - 12/2018
Open Telekom Cloud (OTC) Operating Model
T-Systems Switzerland (Internet und Informationstechnologie)

Build concept for democratised operational model to improve traditional team-silo approach, promote idea throughout teams, build concept to allow for different operational rules divided by OTC-tenant


01/2015 - 01/2018
GitLab/Puppet System Management
T-Systems Switzerland

Design, implement and introduce system management solution based on a combination of GitLab and Puppet. Negotiate requirements with customer. Create modular design to allow for separately maintained modules and stages to split responsibilities. Setup server services using docker. Introduce mechanism and train staff.


08/2017 - 09/2017
Paytrans Project
T-Systems Switzerland (Internet und Informationstechnologie)

Work together with developers on SpringBoot application, enable application for SAF and define operational rules. Setup, optimize and manage OS using Puppet. Assist in setting up multi-hop network access and monitoring.


07/2016 - 03/2017
Docker based Ansible Deployment Automation Platform
T-Systems Switzerland (Internet und Informationstechnologie)

Build minimal system model for host-OS using Puppet, refine hiera usage model. Establish multi-stage docker environment. Design docker-based operation model (failover, state externalzation etc.). Evolve playbooks and operational workflows.


06/2015 - 01/2016
Lupenbilder Project
T-Systems Switzerland (Internet und Informationstechnologie)

Build JBoss system model using Puppet. Setup and deploy application on JBoss EAP. Design and implement JBoss multi-instance operating and deployment/staging model. Evolve concept together with developers. Train staff regarding operating model.


03/2015 - 06/2015
Hazelcast cluster platform
T-Systems Switzerland (Internet und Informationstechnologie)

Build system model using Puppet. Implement operating model using SAF framework (see below). Discuss and negotiate requirements with customer


03/2015 - 05/2015
Dead Simple Information System (DSIS)
T-Systems Switzerland (Internet und Informationstechnologie)

Design and implement flexible REST-style monitoring and alerting application for MQ using Python and CherryPy, negotiate alerting requirements


04/2014 - 04/2015
IBM IIB 9 Platform
T-Systems Switzerland

Design, create, and implement installation model for WebSphere MQ / Integration Broker platform built on Linux. Setup platform incorporating customer requirements (e.g. deployment model, logging, failover, backup). Migrate and improve operating model from predecessor Message Broker platform


09/2011 - 09/2012
WebSphere 8.5 platform design and setup
T-Systems Switzerland (Internet und Informationstechnologie)

Evaluation of different platform approaches (IBM WorkLoad Deployer, Cell based, Jobmanager based). Bid preparation in corporation with sales department. Design and implementation of two separate platform architectures („Low End“ and „High End“). Design and implementation of automated setup routine. Build collaborative model to enhance cross division teamwork. Design and implement simplified deployment process using ant.


06/2012 - 08/2012
Standalone Application Framework (SAF)
T-Systems Switzerland

Architectural design of different approaches (solitary and coexisting). Design and evolve (together with development teams) minimalistic requirements for efficient operation. Design and implement deployment/staging and operation model using standard Linux tools (e.g. git, ssh, rsync, bash, python).


01/2012 - 06/2012
Managed Environment (ME)
T-Systems Switzerland (Internet und Informationstechnologie)

Establish minimalistic, robust and clientless mechanism to synchronize code artifacts over groups of Linux machines. Develop modular design to allow for separately maintained modules to split responsibilities. Invent concept to allow at-sync-time artifact merging of arbitrary module combinations.


Reisebereitschaft

Verfügbar in den Ländern Deutschland
Raum Heidelberg und Remote

Sonstige Angaben

Principles of thought
  • Useful solutions evolve from thoughtful modelling
  • Diverse input improves architecture
  • Architecture leads, the toolset follows
  • Simplicity is key
Profilbild von Stefan Steinert IT Engineer aus Heidelberg IT Engineer
Registrieren