Meet the Team

Get to know the people leading the way for Zetta.​

Dr. Nathan Harman
Managing Director
BSc, BVMS (Hons), PhD

Nathan is a seasoned leader in the Australian IT sector with a track record of building successful businesses from the ground up. His career began with the founding of Harman IT in 1991, and by 2001 the business had expanded to a team of 120. After selling Harman IT to the multinational Marconi plc (now Ericsson), Nathan co-founded Zetta Group in 2004 under his leadership, Zetta has become a prominent provider of IT solutions, with a strong commitment to service excellence and a significant footprint in the WA market. Nathan is passionate about developing Zetta’s capabilities and remains focused on expanding the company’s impact and reach.

Andrew Speirs
CEO
BA (Hons), M. Acc, CPA, CMA, Grad Dip ARMCG, GAICD

Andrew is the CEO of Zetta, bringing over 20 years of executive experience in finance, governance and operations. Since joining as CFO in 2017, he has played a key role in strengthening Zetta’s financial foundation, driving growth, and leading the business through transformation.

Andrew’s leadership is characterised by his ability to build effective and positive relationships, foster collaboration, and drive innovation. He has a proven track record of guiding teams through complex challenges and ensuring financial stability and compliance. Under his leadership, Zetta became the first Perth-based IT company to launch a Reconciliation Action Plan—reflecting his dedication to inclusivity and community engagement.

Carlo Calleri
Sales Manager
Trusted Advisor, WA ICT Leader

Carlo is a seasoned IT sales leader with over 30 years of experience helping organisations navigate complex challenges through technology. With a consultative approach and a strong focus on client relationships, he has delivered outcomes across WA’s mining, energy, government and commercial sectors in senior roles at NEC, Infosys, Ajilon, Denver Technology and Brennan IT.

Carlo leads the sales function with a commitment to delivering value, building trust, and forming long-term partnerships. He’s passionate about supporting WA businesses and driving results that matter.

Zico Grinion
Professional Services Manager
Microsoft 365 Administrator, Azure Solutions Architect

Zico’s career began in the Royal Air Force in 2006, where he developed a unique blend of technical expertise and strategic insight while supporting the Eurofighter Typhoon fleet. A Microsoft-certified expert in Azure, M365, and modern work solutions, Zico is passionate about using technology to empower people and brings a ‘people first’ approach to management. Known for his ability to simplify complex topics, he is a valuable resource for clients and colleagues. Zico’s ambition and strategic vision play a key role in driving our company’s success.

Simon Bendotti
Operational Services Manager
BA Sc (Maths)

Simon is an ITIL-certified Operational Services Manager with over 20 years of experience in delivering IT services across the resources, energy, and government sectors. His expertise includes client liaison, team leadership, change management, and contract management. Before joining Zetta in 2016, Simon held Service Delivery Management roles with global Managed Services providers CSC and Fujitsu. At Zetta, he initially managed key Managed Services accounts and has since advanced to lead the broader Operational Services team.

Vesna van Biljon
Finance Manager
CPA

Vesna is a CPA-qualified Finance Manager with over 10 years of experience in the information technology and professional services sector. Since joining Zetta in 2019, she has focused on optimising systems and processes to enhance operational efficiency and support the company’s growth. As a member of the Senior Leadership Team, she collaborates closely with the directors to drive strategic initiatives. Before joining Zetta, Vesna held several senior financial management roles in the logistics and agricultural industries, having started her career in public practice, specialising in audit and risk management.

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