Our Directors
![](https://abacus.ie/wp-content/uploads/2017/07/Derek.jpg)
Derek O’Callaghan
Managing Director
Derek has over 30 years experience in the computer industry, with extensive knowledge of network operating systems, network communications, application packages and project management. This experience was gained working with Sharptext here in Ireland and later with BML in Kenya. Derek returned to Ireland in 1992 and formed Abacus Systems. in 2014 Derek graduated with BSc in Psychology.
Eoghan Johnson
Business Development Director
Eoghan joined Abacus Systems in 1996 and he holds a BBS, MBA and is a graduate of the Marketing Institute of Ireland. He has worked in Sales Management roles for almost 30 years and also holds certifications from Microsoft, Cisco, HP and other vendors. Eoghan is responsible for Business Development.
![](https://abacus.ie/wp-content/uploads/2017/07/Eoghan.jpg)
![](https://abacus.ie/wp-content/uploads/2017/07/Dave.jpg)
David McDonald
Sales Director
David has a BA from UCD and 19 years extensive IT experience working first with Dell Computers Management Information Systems team before joining Abacus Systems as a senior network engineer, pre-sales technical consultant and account manager. David is VMware Certified Professional and his main areas of expertise are project management, design and implementation, IT security, business continuity, enterprise switching and routing architecture, IP telephony and a storage area network specialist.
Stephen Mullin
Technical Director
Stephen joined Abacus Systems in 1997. Stephen is a Microsoft Certified Systems Engineer, VMware Certified Professional and Mitel Certified Professional with 20 years experience in Microsoft, HP, Dell and Cisco solutions. Stephen has been the lead engineer on most of Abacus Systems major projects, including IP Telephony, Virtualistaion, Network Infrastructure, Business Continioty, Storage Area Networks and WAN connectivity.
![](https://abacus.ie/wp-content/uploads/2017/07/Steve.jpg)
Directors
![](https://abacus.ie/wp-content/uploads/2017/07/Derek.jpg)
Derek O’Callaghan
Managing Director
Qualified Novell Certified NetWare Engineer (CNE), Compaq Accredited Systems Engineer (ASE). Derek has over 30 years experience in computer connectivity, with extensive knowledge of network operating systems, network communications, application packages and project management. This experience was gained working with Sharptext here in Ireland and later with BML in Kenya. Derek returned to Ireland in 1992 and formed Abacus Systems. in 2014 Derek graduated with BSc in Psychology.
![](https://abacus.ie/wp-content/uploads/2017/07/Eoghan.jpg)
Eoghan Johnson
Business Development Director
Eoghan joined Abacus Systems in 1996 and he holds a BBS, MBA and is a graduate of the Marketing Institute of Ireland. He has worked in Sales Management roles for almost 30 years and also holds certifications from Microsoft, Cisco, HP and other vendors. Eoghan is responsible for Business Development.
![](https://abacus.ie/wp-content/uploads/2017/07/Dave.jpg)
David McDonald
Sales Director
David has a BA from UCD and 19 years extensive IT experience working first with Dell Computers Management Information Systems team before joining Abacus Systems as a senior network engineer, pre-sales technical consultant and account manager. David is VMware Certified Professional and his main areas of expertise are project management, design and implementation, IT security, business continuity, enterprise switching and routing architecture, IP telephony and a storage area network specialist.
![](https://abacus.ie/wp-content/uploads/2017/07/Steve.jpg)
Stephen Mullin
Technical Director
Stephen joined Abacus Systems in 1997. Stephen is a Microsoft Certified Systems Engineer, VMware Certified Professional and Mitel Certified Professional with 20 years experience in Microsoft, HP, Dell and Cisco solutions. Stephen has been the lead engineer on most of Abacus Systems major projects, including IP Telephony, Virtualistaion, Network Infrastructure, Business Continioty, Storage Area Networks and WAN connectivity.