Our Executive Team

Giles Nunis | Chief Executive

Giles has a wealth of experience and a deep understanding of the health and technology sectors, which he demonstrated on the HSS Board.

Over his career, Giles has also served in various senior leadership roles in both government and industry. Prior to joining HSS, he was Executive General Manager, Digital Transformation at the WA Primary Health Alliance (WAPHA), where he led major initiatives to modernise and streamline healthcare delivery. 

Known for his strategic vision and commitment to digital transformation, Giles has a proven track record of delivering impactful change across complex systems.  

“I look forward to helping shape one of the most significant digital health transformation journeys in Western Australia—one that empowers health service professionals and ultimately benefits all Western Australians.” 

Ralph Bates | Executive Director, Customer Experience

Ralph joined HSS in 2018 as Executive Director, Customer Experience and through his extensive executive career has ensured the customer is put at the heart of the organisation’s purpose. His experience has led him to successfully develop and execute a number of enterprise customer strategies and lead customer-focused transformation.

In 2018, Ralph was focused on establishing the new Customer Experience business unit, developing customer-focused service level agreements (SLAs) and key performance indicators (KPIs). At the same time, he established a more formal mechanism for HSS to manage performance and simplified how customers contact HSS by implementing an enterprise contact centre.

Since 2020, Ralph led the development and delivery of several key COVID-19 digital applications, including SafeWA, VaccinateWA and the WA Health contact tracing systems. He’s also been responsible for HSS' Business Continuity response during the pandemic – ensuring our organisation could continue to support our customers to provide excellent health care to the WA community.

Anthony Lenzarini | Acting Chief Information Officer

Tony has over 30 years’ experience in the digital ICT industry, dedicating most of his professional career to the WA public health industry, leading large multidisciplinary teams across different ICT functions and digital programs.

He is a passionate senior leader who is solution-focussed and people-oriented and will continue to align and improve HSS ICT services to the WA public health system.

Chad Martino | A/Executive Director, Transformation and Strategy

Chad has worked in the WA public sector for the past 16 years, including six years in a senior executive role at the Department of Health. 

Chad brings a wealth of knowledge and experience across diverse portfolios, in particular Government and stakeholder relations.

An experienced health leader, Chad specialises in issues and crisis management, corporate strategy, stakeholder engagement, policy implementation, government relations, change management and strategic leadership.

“HSS has an ambitious reform agenda that will make a positive difference across our broad health system. I am looking forward to working with the leadership team to continue to drive improvement and build on our success to date.”

Sam Matyear | Acting Director, Office of the Chief Executive

Sam is a strategic leader with broad experience in organisational transformation, stakeholder engagement, and complex program delivery across government and industry.

As Director of the Office of the Chief Executive, Sam leads HSS’ governance, risk and compliance, integrity, audit, communications, and Board liaison functions, supporting the Chief Executive to deliver on organisational priorities and strengthen accountability across the WA health system.

With a background in politics, corporate affairs, and strategic transformation, Sam has deep experience advising senior leaders and aligning diverse stakeholders behind shared goals. He is passionate about building values-driven teams and ensuring their work strengthens not only systems and processes, but also culture, trust, and public value.

“I’m passionate about leading with integrity and purpose, helping shape a health system that’s connected, efficient, and responsive to the needs of the community.”

Julie Mount | A/Executive Director, Program Delivery

Julie has worked at HSS for over a decade, with seven of those years as the Director of Applications (HIN) and subsequently Program Director for the HSS Peel Health Campus program. 

She has extensive program delivery and ICT experience, leading the implementation of HSS ICT for the Perth Children’s and Fiona Stanley Hospitals and delivering the Digital Information Security and Laboratory Information System programs.

Prior working in the WA Health system, Julie worked in the defence and telecommunications industries, managing software development projects with teams around the world (India, USA, Singapore and China) and established the Motorola Australia Software Centre in WA as part of their global Software Development team.

Siobhán Mulvey | Executive Director, Workforce and Organisational Development

Siobhán joined HSS in May 2018 with a strong commitment to the development of an organisational culture that supports, encourages and rewards the achievement of business outcomes.

With more than 25 years’ experience as a senior executive in both the private and public sectors, Siobhán has successfully led the implementation of people strategies to improve culture and engagement.

Before joining HSS, Siobhán held senior management positions in the education, training and mining industries, and provided consultancy services to a number of sporting organisations.

“Continuing our journey to align our culture with our operations will enable us to become a high-performing organisation, focussed on supporting our customers to provide excellent health care."

Neha Patel | Executive Director, Human Resource Management Information System

Neha is a visionary technology and business leader with over 15 years of experience delivering high impact programs across telecommunications, Cloud and enterprise technology with proven success leading large scale portfolios, including Delivery Performance across Telstra’s $400m+ portfolio. 

She has held senior leadership roles in the private sector and through those roles has served the public sector, shaping digital, infrastructure and transformational strategies.  

With a deep understanding of service delivery and the operational realities of large-scale environments, Neha is known for her strategic acumen and dedication to fostering inclusive leadership.  She is passionate about working with purpose and driving meaningful community impact and serves on the boards of multiple not-for-profit organisations. 

Neha joined HSS in 2025 and is leading the delivery of HRplus, a HR, payroll and rostering solution for the WA health system, with rollout commencing in 2025. 

Emily Pestell | Executive Director, Human Resource Management Information System HSS Readiness

Emily established the Office of the Chief Executive (OCE) as a standalone business unit responsible for Governance, Risk, Compliance, Internal Audit, Communications, Ministerial and Parliamentary Liaison and Board Liaison.

Emily has broad business experience with oversight of strategic management issues, risk and governance. She has worked for the Western Australian State Government for the past 10 years; initially at the Department of Finance before joining the WA health system in 2014.

Emily led the establishment and effective implementation of the inaugural HSS Board in July 2020, played a key role in COVID-19 Crisis Management for HSS and has overseen transformation projects in Governance, Information Management and Employer Value Proposition for HSS.

Emily is preparing HSS is readiness for the rollout of HRplus 2025.

Mark Thompson | Chief Procurement Officer

Mark joined HSS in June 2018 and has been leading the modernisation and transformation of procurement and supply services to reduce supply risk while achieving significant return on investment and cost savings across HSS and the WA health system.

Mark has more than 20 years’ experience at a senior management level in the health care, utilities and telecommunications industries in the government, private and not-for-profit sectors. He led numerous multi-disciplinary teams covering procurement, contract management, purchasing, supply chain, fleet, sales and bidding.

Prior to joining HSS, Mark managed a large procurement, warehousing and logistics function, and led one of Western Australia’s largest and most complex fleets. He implemented a major procurement operating model, which included the development of a long-term sustainable supply chain strategy.

“Working together to improve our supply chain will lead to efficiencies and increase the reliability and responsiveness of supply to support the WA health system.”

Sash Tomson | Chief Financial Officer

Sash is a management and finance professional with over 20 years’ experience as a senior executive, having held executive finance positions in the private and government sectors.

Sash has extensive experience in financial management, corporate strategy and policy, evaluating the financial impact of new business initiatives, financial modelling, negotiating and overseeing commercial contracts. As well as health, he has worked in private practice, construction and mining. Sash commenced as CFO of HSS during 2018, and during his time with WA Health he was Acting Chief Executive for PathWest during 2022-23 and Acting Assistant Director-General for the Department of Health up to October 2024.