Aaron Caskey-Demaret

Curriculum Vitae


Table of Contents

Personal Details
Key Skills
Work Experience
nShift (2023-Current)
Gridcore AB/Gompute (2017-2023)
NTT Security (2015-2017)
Praxis Technology Group AB (2014-2015)
Bobby Works AB (2010-2014)
IBM Global Services (2009-2010)
Whitireia Community Polytechnic (2008-2010)
iPredict (Jan, 2009)
TelstraClear Ltd – Enterprise and Government (2007)
Double Negative (2005-2007)
Weta Digital (2001-2004)

Personal Details

Mobile: (+46) 76 884 6592

Email (preferred contact): aaron@caskey-demaret.se

Date of Birth: 20/08/1979

Key Skills

I have experience in the following technologies:

Operating Systems
GNU/Linux (RHEL/Centos/Rocky, Debian/Ubuntu), Windows Server (2003-2012)
Authentication
Active Directory, Samba, SSSD, FreeIPA, Keycloak, LDAP, Oauth/Openid
Configuration Management/Deployment Systems
RedHat Kickstart, Debian Preseed, Ansible, CFEngine, Cobbler, Saltstack, Puppet, Foreman, CloudInit
Backup systems
Bacula, Symantec Backup Exec, Duplicity, BareOS, PGBackrest
Databases
MySQL/MariaDB, Oracle, PostgreSQL
DNS
Bind9, PowerDNS
File Sharing
Samba, NFS, GlusterFS, GPFS, Lustre
Mail Systems
Sendmail, Postfix, Cyrus IMAP, MS Exchange
Monitoring/Metrics
Zabbix, Nagios, OP5, Prometheus, Grafana Logging: Elasticsearch, Opensearch
Scripting
Perl, Python, Bash, PHP
Security
IPtables, PF, Palo Alto, Cisco ASA, Clavister, Crowdstrike
Version Control
Git, CVS, Subversion
Web servers
Apache, Nginx
Virtualisation
VMware ESXi, KVM, VirtualBox, Proxmox, oVirt, Xenserver, LXC/LXD
Containerisation
Docker, Podman
Proprietary Cloud
AWS

Work Experience

nShift (2023-Current)

Gothenburg, Sweden

nShift is a software company that provides parcel book-and-print, checkout handling and other shipping services.

Site Reliability Engineer - Drift Team Lead (2023-Current)

At nShift my duties include:

  • Leading an all new 4 person Drift/Sysops team for the Delivery product

    • Prioritising tasks and focus for the team
    • Ensuring adequate on-call coverage during vacation and sickness
    • Advocating for the team to upper management for pay and resourcing negotiations
    • Interviewing candidates and giving recommendations to management
    • Liaising with other teams to ensure a consistent company focus
    • Working closely with the core development team to ensure the main application runs correctly
  • Discovery and documentation of the previous teams' procedures and technology, including:

    • Salt configuration and custom plugins
    • Supporting hardware in two separate datacentres
    • OS (Ubuntu) version upgrades and patching
    • Postgres clusters with pgBackRest
    • Apache mod_jk, tomcat, and custom deployment and activation scripts
  • Modernising workflows and creating new systems to meet changing company needs
  • Packaging third-party applications for native OS deployment
  • Installing and configuring Prometheus/Grafana and various exporters
  • Managing AWS Migration of core infrastructure

    • Planning migration from Datacentre to Cloud solutions (AWS)
    • Evaluating AWS provided services to replace current bespoke solutions

Gridcore AB/Gompute (2017-2023)

Gothenburg, Sweden

Gompute is a High Performance Computing solution, either customer on-premise or hosted in the Gothenburg datacentre.

Lead Infrastructure Engineer - Gompute Infrastructure (2017-2023)

At Gridcore my duties included:

  • Leading the Infrastructure team

    • Prioritising tasks and focus for the team
    • Ensuring adequate coverage during vacation and sickness
    • Advocating for the team to upper management for pay and resourcing negotiations
    • Liaising with other teams to ensure a consistent company focus
  • Creating Puppet modules to automate system tasks and application deployment

    • Automation of docker containers using Puppet
    • Automation of Slurm configuration using Puppet
  • Administration and development of multiple Foreman and Puppet installations
  • Designing CI flow to package RPMs of in-house and third-party software
  • Design, installation, and maintenance of VM hosting solutions (oVirt, Xenserver and KVM)
  • Developing an automated installation of Prometheus/Grafana and various exporters to clusters
  • Deployment and autoconfiguration of Ansible on a per-cluster basis
  • Network design, configuration and troubleshooting for individual clusters and core infrastructure
  • Site2Site VPN installation and troubleshooting
  • GPFS installation and troubleshooting. Including CES configuration with an LDAP backend
  • General third level customer support
  • Developing solutions to integrate Windows nodes into HPC clusters
  • Overseeing deployment of on-premise customer solutions (including on-site work if needed)
  • Evaluation and migration of primary OS from CentOS to Rocky Linux

NTT Security (2015-2017)

Gothenburg, Sweden

NTT Security provides enterprise security solutions to analyse traffic and protect client networks.

Technical Operations Engineer: (2015-2017)

At NTT Security my duties included:

  • Palo Alto and Cisco Firewall configuration
  • Configuring and debugging High Availability systems and load balancers
  • Modification and development of the local SaltStack deployment system
  • Design and Development of entire new SaltStack deployment system for a new service
  • General first through third level support for a range of international customers including:

    • Implementing RFCs inside customer facing networks
    • Liaising with customers to discuss modifications and improvements to their systems
    • Troubleshooting hardware issues with customer systems
    • Troubleshooting VPN and network issues with customer environments
    • Debugging and implementing new firewall rules for clients
  • Hardware Maintenance of remote systems
  • Server Room mapping and diagramming
  • ESXi support and deployment
  • Network planning and implementation for new intrusion testing environments

Praxis Technology Group AB (2014-2015)

Gothenburg, Sweden

Praxis Technology Group was a start-up that offered remote render-farm solutions to small VFX companies.

I was the CTO and system engineer/architect. As we had only just started, most of my work was very hands on.

CTO/System Architect: (2014-2015)

At Praxis Technology Group my duties included:

  • Design of the infrastructure of a 70 node render farm
  • Software Project Management
  • Software Solution High-level Design
  • Design of bespoke solutions to allow clients to utilise the render farm including:

    • Setting up VPN access
    • Configuring render software and licenses
    • Customising our environment to duplicate the client’s
    • Designing solutions to meet any other client needs
    • Automating the solution to allow rapid building of the client environment from bare metal
  • Hardware Maintenance and Purchasing
  • Server Room design and layout, including cooling
  • Disaster Recovery design and testing

Bobby Works AB (2010-2014)

Gothenburg, Sweden

Bobby is a digital production company that helps leading brands and agencies to develop and visualize communication ideas for film and interactive media.

I worked as the in house System Administer and Technical Support Person.

System Administrator: (2010-2014)

At Bobby my duties included:

  • General desktop support for Windows 7 and OS X workstations
  • Administering and configuring backups using Symantec Backup Exec and Bacula
  • Automating the creation of FTP accounts and administering their use
  • Administering the Windows Domain Controller
  • Integrating new Linux servers into the Windows domain using Samba3 and SSSD
  • Configuring and automating Samba3 for DFS sharing, and virtual file-servers
  • Building and Administering the site router/firewall
  • Setting up web sites for client projects (hosted both internally and using third parties) and installing and configuring CMS systems (mostly in house designed Wordpress sites)
  • Setting up system monitoring with Zabbix
  • Touch screen application prototyping and testing using Python
  • Movie file conversion for broadcast
  • Web development in PHP and JavaScript, including modifications to Wordpress plug-ins
  • Evaluating and purchasing of server hardware
  • Overseeing the general IT infrastructure and budget

IBM Global Services (2009-2010)

Wellington, New Zealand

IBM manufactures and sells computer hardware and software (with a focus on the latter), and offers infrastructure services, hosting services, and consulting services.

I worked in the Linux service team, supporting a number of off-site RedHat servers for clients.

Linux Specialist: (2009-2010)

At IBM NZ my duties included:

  • Administering Linux systems for a number of IBM’s clients:

    • Designing and implementing a security patching regime for a nation-wide government installation running RHEL3 and RHEL4
    • Building physical and and virtual machines for Oracle and DB2 database instances. (RHEL4 and RHEL5)
    • Working closely with the DBAs to facilitate after hours upgrades and maintenance of Oracle and DB2 databases
    • Imaging servers using Acronis TrueImage
  • Continuing development of an asset tracking system (Perl and Python with a PostgreSQL back end)
  • Administering VMware ESX (v2.1, 3.5, 4) guests
  • Updating the CFEngine configuration, monitoring logs and fixing errors
  • On site server installation and maintenance

Whitireia Community Polytechnic (2008-2010)

Wellington, New Zealand

The new Whitireia Journalism programme has a focus on new-media and Internet technologies. To give students real-world contact with the technology, the head tutor, Jim Tucker, set up a live, public news website for the students to display their work.

NewsWire.co.nz Webmaster and Designer: (2008-2010)

At Whitireia Polytechnic my duties included:

  • Administering the Journalism class’s news website: www.newswire.co.nz including:

    • Installing and Upgrading Wordpress (www.wordpress.org)
    • Researching, testing and installing appropriate plug-ins
    • Modifications to the code-base in PHP
    • Tracking traffic usage and storage capacity on the remote host
  • Setting up Google Apps for the newswire.co.nz domain to allow students email and calendar access
  • Designing logos and banners for NewsWire
  • Teaching students how to upload media and stories to NewsWire and how to use their email accounts

iPredict (Jan, 2009)

Wellington, New Zealand

iPredict is a company that sells Market Prediction software. Their public website: www.ipredict.co.nz had the second best prediction rate of the 2008 general election.

They sell the software used on the public site to clients. The client’s sites are hosted at Victoria university along with the public site.

System Administrator and PHP Developer: (Jan, 2008)

During my four week contract at iPredict my duties included:

  • Administering the Xen Virtual server environment:
  • Selection and installation of a blog (Wordpress) and a forum (Phorum)for the iPredict public site, and the private client sites:

    • Writing plug-ins to allow the blog and forum to authenticate with the iPredict software
    • Creating themes for the blog and forum so that they visually integrate with the iPredict websites

TelstraClear Ltd – Enterprise and Government (2007)

Wellington, New Zealand

TelstraClear is the second largest telecommunications company in New Zealand. The E&G division offers enterprise level support for TelstraClear’s largest clients.

Unix Systems Administrator: (2007)

At TelstraClear Ltd my duties included:

  • Operational System Administration of multiple off site clients,consisting of Linux and Solaris servers
  • Installation, configuration and monitoring of RHEL 3 servers for a number of New Zealand based clients
  • Support for the in house Systems Management Framework (SMF)
  • On Call support of servers
  • Research and Development of automation systems for the environment

Double Negative (2005-2007)

London, England

Double Negative is a film post-production facility based in Soho, London.

Systems Administrator: (2005-2007)

At Double Negative, my duties included:

  • System Administration of a heterogeneous environment composed of IRIX, Linux, Windows NT/2000, Mac OS X, and Solaris (with an emphasis on Linux administration)
  • Installation, configuration and monitoring of Tripwire and Osiris on the DMZ machines
  • Configuration and support of the internal mail and news servers
  • Developing wrappers to aid mail administration
  • Administration of MySQL server (v4.0 and v4.1)
  • Desktop Support
  • Administration of Pixar’s Renderman Alfred Tools

Weta Digital (2001-2004)

Wellington, New Zealand

Weta Digital is New Zealand’s largest post-production facility. Specialising in special digital effects for film.

Systems Administrator: (2003-2004)

My responsibilities as a Systems Administrator included:

  • Building and deploying core service machines, including web, mail and DNS/DHCP servers. Including installation of Linux operating system
  • Administration of Network Appliance Filers, Foundry Switches and various Linux and IRIX machines
  • Firewall and Web Proxy configuration
  • Developing an SMS gateway for Nagios, XMPP and email

Render Wrangler: (2001-2002)

My duties as a Render Wrangler included:

  • Administration of renders running on the Linux rendering cluster
  • Maintenance of 1500 machines in the Linux based rendering cluster and assisting in the deployment to 1000 new machines
  • Designing and implementing tools to assist the wrangling team in administering the Alfred queuing software
  • General Technical Support of Irix, Linux and Windows workstations