I am an experienced and certified Linux engineer with a passion for Open Source and Open Standards. Having over 20 years of experience in small to enterprise size companies, more than 10 of these involve projects related to Linux and/or Open Source Software.

My main interest lies with enterprise environments where the need for virtualization, standardisation, automation and documentation is essential.

I am creative in finding solutions, studious and ambitious.

Personal Data

name William Leemans
date of birth 22 February 1973
nationality Belgian
location Heverlee, Belgium
email This email address is being protected from spambots. You need JavaScript enabled to view it.
phone +32 494 118 740

Work experience

UNIX Engineer/Architect (full time) 04/2015 - now

Euroclear, Brussels

  • Provide Expert knowledge to support RHEL environment;
  • Define & implement Ansible to deploy customer applications;
  • Perform various operational tasks involving Virtualization, SAN, Clustering, ...

RHEL Expert & performance analyst (full time) 04/2011 - 04/2015

Belgacom, Brussels

  • Fix vmware hardware upgrade issues caused by VMware API (1000+ servers)
  • Definition & implementation of performance monitoring for all RHEL servers (±3000 servers)
  • Development of various scripts (mainly bash, python, perl), Ansible playbooks and Puppet classes to deploy configuration & various applications
  • Provide support for the hosting platform (Parallels)
  • Migration of ±500 Debian Linux servers to RHEL 5/6
  • Perform various operational tasks involving Virtualization, SAN, Clustering, ...

RHEL Expert (full time) 06/2010 - 04/2011

Federale Politie, Brussels

  • Migrate HPUX systems to RHEL 5
  • Provide technical support for Local Police System administrators
  • Design & implement vSphere 4 test environment

Windows & VMWare architect (full time) 09/2009 - 06/2010

Total Petrochemicals, Feluy

  • Identification & remediation of MOSS 2007 environment shortcomings
  • Migration, consolidation and virtualization of the regional BackOffice to new AD and Windows 2008
  • Definition of Architecture of new industry-specific client/server applications (IUCLID, Chembook, ExEss, PHD)
  • Provide expert support for 7000+ users
  • Migrate out-of-support Windows 2000 Servers to Windows 2003

System engineer (full time) 05/2007 - 06/2009

LMS International, Leuven

  • Define standards & maintain Linux, Unix, VMWare ESX(i) and Windows systems
  • Consolidate AIX, HP-UX and Solaris systems
  • Migration of NIS environment from HPUX to Debian Linux
  • Provide general system engineering and operational support for 1000+ users
  • Migration of existing Exchange 2003 infrastructure to Exchange 2007
  • Migration of mail relay infrastructure to Symantec MessageLabs
  • Migration of the AD Hardware to a new and more performant system
  • Migration of the backup solution to more performant system
  • Migration of AD infrastructure of a bought-up company
  • Update and manage internally developed intranet (php, mssql)
  • Migrate UNIX scripts to Linux (sh, csh, ksh, bash)
  • Revise internally developed user/group creation scripts (ms-dos, VBScript, Powershell)

System engineer (as needed) since 12/2008

Cedexsa n.v., Brugge

  • Design & implementation an internal/external mail relay including virus and spam filters.
  • Provide expert Linux knowledge
  • Design & implementation of VMWare ESX backup



  • Fast learner
  • Extensive *NIX system administration, system automation and orchestration experience.
  • in depth knowledge and experience of configuring and deploying systems in a uniform and scalable way.
  • Experience with project management and leading technical teams


  • Communication
  • Team Player

System Architecture

  • Design security standards and processes
  • Design Lifecycle & security update management processes

System Engineering

  • In depth RHEL internals knowledge
  • Thorough knowledge of Performance analysis & tuning
  • Expert experience automating & deploying using Ansible, Puppet and Red Hat Network Satellite
  • Experience with unattended installation & configuration mechanisms for rapid mass deployment
  • Knowledge of setting up package building environments to build custom rpm packages for distribution
  • In depth experience in designing & implementing monitoring and reporting infrastructures
  • Thorough experience in designing and implementing a multi-customer monitoring and reporting infrastructure.

Operating Systems / Software

  • Excellent knowledge of following Linux distributions: Red Hat Enterprise Linux, CentOS, Fedora, Debian, Ubuntu, Gentoo
  • Excellent knowledge of the following Automation/Orchestration tools: Ansible, Puppet
  • Experience troubleshooting and administering Linux, HP-UX, IBM AIX, SUN Solaris systems
  • Experience managing and integrating RHEV/KVM and VMWare virtualization solutions
  • Experience deploying & managing high-available critical systems, including load-balancing, clustering and disaster recovery of web servers, firewalls, intrusion detection systems.
  • Expert experience in compiling, installing, and configuring of Linux system software (e.g. NFS, Samba, lpd and cups, Postfix, Amavisd, Bind, DHCP, XFree86, Apache, ssh, ntpd, Snort, RRDtool, Nagios, Webmin, KVM, …)
  • Experience with various markup languages (YML, HTML, SGM, XML, CSS)
  • IPv4 (TCP/UDP), ICMP, ARP and protocols like IRC, FTP, SMTP, HTTP, NNTP, POP3, IMAP, DHCP, IPsec, ...
  • Various SQL flavors (MySQL, MariaSQL, PostgreSQL, sqlite).

Programming and Scripting Languages

  • Bash
  • Javascript
  • Perl
  • PHP
  • Python


  • Dutch native
  • French fluent (speaking, reading, writing)
  • English fluent (speaking, reading, writing)
  • German basic (speaking, reading)



  • ITIL Foundations v2.0
  • Red Hat Certified Engineer (805007084029417) - 100%
  • Red Hat Certified Technician (605007366014897) - 100%