Yma is a not-for-profit social enterprise, existing to create possibilities for exceptional care for the people of Wales now, and for future generations

The viability and future shape of our health and social care system is being tackled by many different organisations and agencies in Wales.

The lens through which we undertake our work, advocating from grassroots, being open to all possibilities without being tethered to the status quo (even rejecting it where needed) and actively seeking alternative ways for the system to exist, sets us apart.

This makes Yma unique in Wales.

Meet our team

Samantha Horwill
Samantha Horwill
Co-founder & Managing Director

Sam has 15 years of experience working in and with the NHS across the UK, developing and delivering new community-led service models to aid collaboration and innovation.  In 2019 she was invited to share her work in the NHS in Wales by TEDx Aberystwyth.

As co-founder and MD of Yma, her role is to bring alive our purpose – to create the conditions where primary care in Wales can thrive now, and for future generations.

Sam is also a passionate advocate for renewable technology and an electric vehicle enthusiast, seeking ways to accelerate progress in this area at a local and national level.

Sarah Bartholomew
Sarah Bartholomew
Company Director

Sarah’s focus is on connecting the journey of Yma to the wider world, ensuring we support people to live better lives.

She looks to develop new partnerships, collaborations and opportunities to further our purpose.

Dr Julia Pirson
Dr Julia Pirson
Projects Lead

Julia is a post-doctoral chemist with a background in lithium-ion battery materials and teaching.  

Julia joined Yma in 2020 and is leading our project management function. The project management team takes on a variety of projects both external and internal, some of which are on our Projects page. We are always interested in doing new things, or learning how to do familiar things better.

Julia enjoys finding creative solutions to problems, playing with spreadsheets, and illustration.

Matthew Riley
Matthew Riley
Data Protection Officer

Matthew is the Data Protection Officer ‘DPO’ for Yma. This means that he works with the team at Yma around all aspects of information governance and data security. It is easy to just see this as a security role: Matthew thinks it is more about using information in a way that creates a learning culture and supports innovation, whilst at the same time keeping the promise that we make to our staff, partners, customers and patients to keep it safe.

Matthew has a long-standing connection with Yma, having worked with Sam Horwill when ‘Here’ was founded in Brighton, in 2008, where he is still a Non-executive director and Chief Information Officer.

Kari Greengross
Kari Greengross
Project Support Officer

Kari comes from a background of working with children with developmental delays or disabilities and their families. She joined our team in September 2022 and brings her experience of working as part of a multi-disciplinary team and a passion for helping underserved and vulnerable communities.

Kari's ideal pastime is reading and writing poetry, but in reality, she spends a lot of time building with and deciphering Lego instructions and volunteering as Responsible Individual for the playgroup her children attended.


We're proud of our people, and our past colleagues.
Chloe Crowl
Role within Yma
Project Support Officer

Chloe worked with us as a Project Administrator and later as a Project Support Officer from July 2021 to March 2023. During her time here Chloe supported the development of the team's project and programme management processes and was able to develop her interests in planetary health, social prescribing and health access equity. Chloe will be undertaking an MSc in Public Health and Promotion and is looking forward to growing her knowledgebase further.

William Mackintosh
Role within Yma
Interim Clinical Director

Will has worked as a GP partner in West Wales for 10 years and has a special interest in medical education and leadership.  Will worked as part of the Yma team providing clinical leadership, in particular ensuring that the core values of primary care are at the centre of our projects for the benefit of patients across Wales. 

Dawid Rumian
Role within Yma
Project Administrator

Dawid worked as a Project Administrator at Yma for approximately eight months in 2021. During this time, he supported the company's financial and administrative activities while completing his bachelor's degree at the university. This was his first professional work experience, and he learned many transferable skills, such as task prioritisation, communication, and teamwork. Afterward, he held leadership positions in the logistics and banking industries. Currently, Dawid is working as an Accounting and Administration Manager for Private Equity Funds at State Street.

Rhys Jones
Role within Yma
Product and Partnership Lead

Rhys worked at Yma from 2021 to 2023 as the Product and Partnership Lead, supporting practices in seeking solutions for their needs. After creating excellent connections both within the team and across the country, Rhys moved on to pastures new as an Accounts Development Manager for Lloyds Pharmacy Clinical Homecare.


Here we hope to answer some common enquiries.
If you'd like to know more, please feel free to get in touch.

Where is Yma based?
We are based in AberInnovation just outside of Aberystywth, making us well placed to work across Wales

How can I contact the Yma team? 
To contact us you can email Yma@dymani.cymru or phone 01970 823003

We’re here for you
If you have any ideas on how we can accomplish our goals within Health and Social Care, or would like to get involved, we’d love to hear from you.
Get in touch