Executive Team

Paul Rosebush

Chief Executive Officer

Paul Rosebush has had a broad leadership career in health care and social services. He commenced his career in the Canadian Forces as a Social Work Officer and participated in deployments to Bosnia and Rwanda. Over his twenty year career in the CF Paul was posted to numerous bases across the country where he developed expertise in individual and family counselling as well as expertise in Suicide Prevention, Critical Incident Stress, and PTSD.

Following his career in the CF Paul began a career in the private and non-profit sectors with leadership roles at Durham Family Services, and Community Living Ajax-Pickering and Whitby followed by CEO roles in three hospital corporations including the Hay River Health Authority in the North West Territories and the Haliburton Highlands Health Services in Central Ontario and the South Bruce Grey Health Centre in South Western Ontario.

Paul is adept at providing leadership to complex multi-sited organizations that deliver a variety of health and community services. With a clear focus on client and patient centred care Paul has worked with his teams to build service capacity and to develop services that are highly effective and highly regarded by clients and patients. Paul has supported the development of a strong continuum of health care and social services throughout his career and has a reputation for excellent stakeholder management and forging innovative partnerships that benefit clients and patients. Paul approaches leadership from a servant-leader perspective and supports his teams to be high performing and effective. 

As a fortunate cancer survivor Paul knows how important it is to make a positive impact on the world and for those we engage with while we can. Paul also strongly believes that there is no higher responsibility for society than to ensure the safety and wellbeing of children. He is proud to be a CAST team member and it’s CEO.

After having raised a family of four children with his wife Julia, Paul is now happy to dote on his mini-Dachshunds Dylan and Daisy with Dylan having been named after his deep admiration for Bob Dylan.  Living in the same city as his favourite sports teams is also a dream come true for Paul.

Read the full version of the mandate letter


Mahesh Prajapat

Chief Operating Officer

Mahesh Prajapat has over 25 years of combined experience in the areas of Social Work and practice and leadership. Prior to joining CAS of Toronto as the Chief Operating Officer, he was the Director of Service at the Children's Aid Society in Peel. He possess a Bachelor of Social Work Degree from Lakehead University, and a Masters of Social Work from University of Toronto, and completed Leadership designations with Schulich School of Business, leading organizational change initiatives with Excellence Canada, and was a Clinical Panel Member with the Office of the Children's Lawyer. Mahesh is a strong advocate and champion of Diversity, Equity and Inclusion; organizational excellence and strategic thinking and improvement, strongly committed to building partnerships with the community to ensure families are strengthened and children remain safe, healthy and strong.


Anthony Battista

Chief Financial Officer

Anthony is a senior financial executive with over 17 years of diverse experience in accounting, reporting, budgeting, business advisory services and national IT implementations.  Prior to joining CAS, Anthony operated in the Ontario Broader Public Sector as the Deputy CFO at Baycrest Health Sciences.  Anthony enjoyed an 11+ year career at KPMG commencing in 2000 during which he obtained his designation as a Chartered Professional Accountant.  He holds a Bachelors of Business Administration from the Schulich School of Business at York University.  Anthony is a motivating leader who builds and maintains positive relationships at all levels and delivers value-added results.


Marnie Lynn

Chief Human Resources Officer

Marnie’s roles as a Director and Senior Executive, in Human Resources in both the Healthcare and Child Welfare Services sectors have allowed her to develop an innovative and effective leadership style, utilizing exceptional team building, negotiation and change-focused skills, while working with diverse stakeholders to build consensus and achieve objectives.

Her strength is being able to integrate Human Resources seamlessly into all aspects of an  organization and to partner with all levels of management and Union to maximize opportunities and provide quality organizational development.

She currently sits on several Healthcare and Child Services Boards and Committees at Nucleus Independent Living and within the Halton Mississauga LHIN.