Summary
Overview
Work history
Education
Skills
Accomplishments
REFEREES
INTERESTS
PERSONAL DETAILS
Affiliations
Certification
Timeline
Generic

Theo Cronhelm

Edgware,Middlesex

Summary

IT professional with extensive experience in system maintenance, fault management, and data centre operations. Proficient in Microsoft Office Suite, documentation, and disaster recovery processes. Expertise in backup administration, patch management, and training development, ensuring high operational efficiency. Attentive and conscientious with customer facing skills and a passion for detail.

Overview

42
42
years of professional experience
6
6
years of post-secondary education
3
3

Certifications

Work history

Assistant Tutor

Whitefield College
11.2008 - 07.2009
  • Providing tutorial assistance for the ECDL course at Whitefield College.
  • Delivered ECDL training to adult learners through workshops and seminars.
  • Created study materials to aid knowledge recall during exams.
  • Collaborated closely with lead tutor on syllabus delivery, ensuring consistency across teaching methods.
  • Explained complex concepts clearly, simplifying the learning process for students.
  • Managed smaller tutorial groups to facilitate personalised attention. and offered one-on-one academic support, ensuring individual improvement goals were met.


Voluntary Teaching Assistant

Edgware Infant School
Edgware, Middlesex
11.2008 - 07.2009


  • Assisted in preparation of classroom materials to facilitate efficient lessons.
  • Managed administrative tasks in the school office using Microsoft Office tools.

Infrastructure Engineer - OpenVMS/Wintel

Transport for London
London
09.2013 - 01.2026
  • Provided 24/7 technical support for OpenVms/Wintel infrastructure and applications.
  • Assisted in managing and maintaining systems proactively.
  • Ensured compliance with operational and incident/service request management SLAs/OLAs.
  • Administered data security measures for infrastructure.
  • Coordinated disaster recovery efforts with business units.
  • Documented processes and procedures effectively.
  • Collaborated with teams and suppliers on improvement initiatives.
  • Minimised technical issues through regular maintenance of server systems.
  • Produced reports and data analyses using Word, Excel, and PowerPoint for senior management.

Secondment in Data Control

Transport for London
London
03.2025 - 07.2025

Assisted in analysing data related to IT and application access for third parties and internal staff.


  • Utilised Excel for data preparation and analysis from various sources to uphold system security integrity.
  • Collaborated with IT teams to ensure post-analysis actions were executed and resolved.
  • Completed tasks within specified deadlines.
  • Used Microsoft Word, PowerPoint, and Power BI to create procedural and related documentation.
  • Supported team members through respectful interactions and a willingness to help.

Data Centre Operator

Transport for London
London
11.2009 - 09.2013
  • Monitored TFL systems and Networks using Dynatrace providing first-line fault fixes and escalation where necessary.
  • Created and maintained documentation and implemented site access & management procedures for principal data centre.
  • Managed and collaborated if required with internal teams to ensure execution and resolution of user requests. .
  • Performed Server installations and copper and fibre optic cable patching within Data Centre.
  • Supported major incident management process outside business hours from May 2010 to March 2012.
  • Compiled various IT reports using Word, Excel & PowerPoint for internal users and management presentations.

Computer Operator

LCH Clearnet
London
07.2007 - 09.2008
  • Provision of 24/7 monitoring and first line support of OpenVMS, UNIX & Wintel infrastructure using industry infrastructure monitoring tools .
  • Incident management and collaboration with internal teams and 3rd parties to ensure swift resolution of technical issues and minimise disruption to daily operations.
  • Provided Level 1 support for service desk out of hours and incident management if required.
  • Completed all scheduled infrastructure batch, backup and data processing to SLA requirements.
  • Implemented and collaborated with support teams to deliver disaster recovery and change requirements.
  • Constant improvement process alongside procedural document creation and management.

Computer Operator (Contract)

Gartmore Investments
London
12.2003 - 08.2004
  • First line support and 24-hour monitoring of UNIX, AS400, Wintel and OpenVMS servers and network protocols.
  • Incident management/resolution and provision of incident reports.
  • User requests on all infrastructure. .
  • Provided out of hours service desk calls with incident management if required .
  • Scheduled backup , batch and data processing on all infrastructure.


Computer Operator (Contract)

BNP Paribas
London
11.2000 - 12.2003
  • System management and first line support on network protocols, OpenVMS, UNIX , Wintel infrastructure.
  • Scheduled backup, batch and data processing on all infrastructure in accordance to SLA requirements.
  • Incident management and First line support,
  • Provisions of Service Reports to internal users and management.
  • Actioned user requests on all infrastructure .
  • Document creation and management of procedures to ISO9000 requirements.
  • Global service desk support and incident management outside of UK business hours.


Computer Operator (Contract)

Capita Business Services
London
10.1998 - 11.2000
  • Worked flexibly on shift basis to provide 24/7 first support for all IT Infrastructure and Network Protocols
  • Troubleshot and diagnosed systems to identify and resolve hardware and software issues.
  • Coordinated with other IT teams in planning system and software upgrades
  • Assisted in reducing system downtime for improved productivity through systematic troubleshooting.
  • Resolved technical issues swiftly to minimise disruption to daily operations.
  • Drafted standard operating procedures for system operations.
  • Increased system efficiency by conducting regular computer hardware and software maintenance.
  • Worked with IT teams to implement and test disaster recovery procedures.
  • Worked with Excel to analyse data and produced presentations from subsequent data for management analysis.

Computer Operator (Contract)

Citibank NA
London
04.1998 - 10.1998
  • Resolved technical issues swiftly to minimise disruption to daily operations.
  • Performed routine checks on computer systems, maintaining optimal functionality.
  • Managed user accounts and permissions for secure access controls.
  • Provided customer support remotely or onsite as required, solving technical queries efficiently.
  • Monitored network performance regularly, ensuring smooth business operations.
  • Increased system efficiency by conducting regular computer hardware and software maintenance.
  • Installed new hardware, software updates and security patches.
  • Coordinated with IT teams to troubleshoot and resolve Infrastructure & network connectivity issues.
  • Responded to user queries and issues with timely technical support.

Computer Operator (Contract)

Barclays Capital
London
01.1998 - 04.1998
  • Provided 24/7 first line support to all Infrastructure, desktop and Network Protocols.
  • Prepared computers for data processing schedules.
  • Installed new hardware, software updates and security patches.
  • Operated computers and data processing equipment in line with established procedures.
  • Drafted standard operating procedures for system operations.
  • Worked with Word & Excel to analyse data and present to audiences.
  • Monitored network performance regularly, ensuring smooth business operations.
  • Performed routine checks on computer systems, maintaining optimal functionality.

Computer operator

Reuters
London
09.1988 - 12.1997
  • Worked flexibly on 24/7 shift basis to provide first line support to all Infrastructure and associated applications.
  • Managed user accounts and permissions for secure access controls.
  • Scheduled and conducted routine maintenance tasks thus preventing hardware/ software malfunctions and ensuring data security
  • Integrated new software and changes to applications to optimise performance.
  • Drafted standard operating procedures for system operations.
  • Produced presentations from spreadsheet data for management analysis.
  • Attended to ad hoc user IT requests.
  • Prepared IT Infrastructure for data processing and backups.
  • Monitored network performance regularly, ensuring smooth business. operations.
  • Troubleshot and diagnosed systems to identify and resolve hardware and software issues.

Computer Operator

Autofile Software
Slough, Berkshire
09.1987 - 09.1988
  • Provided first-line support for network protocols across OpenVMS, UNIX, and Wintel infrastructure.
  • Managed incidents and delivered service reports to internal users and management.
  • Scheduled and executed backup batches and data processing according to SLA requirements.
  • Addressed user requests across all infrastructure.
  • Created and maintained documentation using MS Office Suite for procedures in compliance with industry standards.
  • Delivered first-line internal support and global service desk operations.

Computer Operator

House of Frazer
London
02.1986 - 08.1987
  • Executed routine checks on computer systems to support optimal functionality.
  • Assisted in increasing system efficiency through regular maintenance of computer hardware and software.
  • Managed stock allocation for all House of Fraser stores across the UK using bespoke software.
  • Facilitated data entry for sales and supported management with data analysis reports.
  • Conducted training sessions for staff on new IT protocols to enhance adherence to best practices.
  • Collaborated with IT professionals in planning system upgrades and introducing new technologies.

Youth Work Experience

ICL Computers, Dublin
Dublin, Republic of Ireland
10.1983 - 11.1984
  • Assisted in creating and managing documentation using data preparation systems.
  • Supported IT team in management of backup processes.
  • Facilitated organisation of data entry tasks.

Education

Leaving Certificate - Secondary School

Technical Institute Ringsend
Dublin
01.1982 - 01.1983

Intermediate Certificate -

Wesley College
Dublin
09.1975 - 06.1980

Skills

  • Customer facing IT skills
  • Excel, PowerPoint & Power BI
  • Backup and restore administration
  • Documentation and process management
  • System maintenance and assurance
  • Fault management procedures
  • Data centre operations knowledge
  • Training and Development
  • Disaster recovery
  • Patch management
  • Conscientious & Attention to Detail

Accomplishments

  • Co-ordinated working on site and at remote sites following a Cyber attack to reset user passwords securely , support and install Microsoft Authenticator over 33,000 user devices . Established a collective dashboard to measure progress and collaborated with various management teams to ensure efficient completion of the project. This work was rewarded with several internal awards recognising the complexity, organisation and efforts required.
  • Collaborated with TfL SCCM team and completed a project to rewrite all rules monitoring application and licence usage. This work enabled the business to achieve accurate efficient licence and application usage thus providing considerable savings.
  • Part of a team that successfully completed proof of concept testing and deployment of new OpenVMS compatible infrastructure, operating systems, cutover of all associated applications and successful post implantation testing.
  • Undertook a project upon arrival in TfL to complete a full analysis, documentation and transition of OpenVMS estate and all its procedures to the new Data Centre Shift Operations team based in Woking DC(a).
  • Collaborated with other teams to construct and install new infrastructure required for the London 2012 Olympics.
  • Implemented various projects to transition first line fault fixing work previously performed by support/technical teams out of hours as part of continuous improvement
  • SME for various applications and provided documentation, training plus out of hours support.
  • Assisted in the creation and maintenance of a technology knowledge bible in varying formats which enabled IT staff to centralise knowledge and incident management experience.

REFEREES

Available on request

INTERESTS

Fitness and training member of Crossfit Harrow  (completed the Dublin Marathon in 2003 and Amsterdam Marathon 2004)., Member of Surrey County Cricket Club., Former playing member of Phoenix Cricket Club, Dublin., Foreign Travel,  Audio Visual and HiFi

PERSONAL DETAILS

  • Nationality: Ireland
  • Marital Status: Married
  • Driving Licence: Full and Clean

Affiliations

  • Fitness - Member of Crossfit Harrow.
  • Member of Surrey County Cricket Club.
  • Passion for Audio Visual and HiFi.

Certification

OpenVMS Systems Management

ITIL Foundation 3

Data Centre Management

Kepner Tragoe Incident Management

EDCL (Certificate in Microsoft Office and Outlook)

Timeline

Secondment in Data Control

Transport for London
03.2025 - 07.2025

Infrastructure Engineer - OpenVMS/Wintel

Transport for London
09.2013 - 01.2026

Data Centre Operator

Transport for London
11.2009 - 09.2013

Assistant Tutor

Whitefield College
11.2008 - 07.2009

Voluntary Teaching Assistant

Edgware Infant School
11.2008 - 07.2009

Computer Operator

LCH Clearnet
07.2007 - 09.2008

Computer Operator (Contract)

Gartmore Investments
12.2003 - 08.2004

Computer Operator (Contract)

BNP Paribas
11.2000 - 12.2003

Computer Operator (Contract)

Capita Business Services
10.1998 - 11.2000

Computer Operator (Contract)

Citibank NA
04.1998 - 10.1998

Computer Operator (Contract)

Barclays Capital
01.1998 - 04.1998

Computer operator

Reuters
09.1988 - 12.1997

Computer Operator

Autofile Software
09.1987 - 09.1988

Computer Operator

House of Frazer
02.1986 - 08.1987

Youth Work Experience

ICL Computers, Dublin
10.1983 - 11.1984

Leaving Certificate - Secondary School

Technical Institute Ringsend
01.1982 - 01.1983

Intermediate Certificate -

Wesley College
09.1975 - 06.1980
Theo Cronhelm