The Team

Lorin Gresser

Chief Executive Officer
Lorin founded Dem Dx in 2015 after graduating from medical school and has been the CEO of Dem Dx ever since. As well as her medical degree from King's College London she has a MA in Natural Sciences from Cambridge University and an MBA from Harvard University.

Steve Varley

Chief Technical Officer
Steve has over 30 years experience in open systems software design, including 10+ years in mobile app development. Steve holds a BA in Computing Science from Teesside University.
Michael Steel

Michael Steel

Following a successful career in strategy consulting, Michael founded Greenbrook Healthcare in 2006 and grew it to become the largest provider of NHS urgent treatment centres in the country. In 2019, the Greenbrook business was successfully sold to Totally plc with £40m+ turnover, 700+ staff and a reputation for high quality and safe service provision. Michael holds an MBA from INSEAD and an MPhil. in Economics from Oxford University.
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Sally Johnson

Sally is a practicing GP with 30 years experience in the NHS. Alongside her clinical roles she has worked as the Chief Medical Officer of NHS and International Private primary and urgent care organisations. She has expertise in developing and delivering high quality, innovative and safe services. Her interests include pathway innovation, clinical governance, telemedicine, regulatory compliance and workforce development. As well as supporting Dem Dx Sally is a practicing GP, CQC inspector and Medical Examiner.

Mariane Melo

Chief Medical Officer
Mariane founded the first spin-off of her university and several awards including competitions in Finland and MIT. She holds an MBBS, Federal University of Minas Gerais Brazil and King's College London, UK.

James McAllister

Lead Developer
James has over 20 years experience as a web developer across multiple industries. Until recently, he shared this experience as a teacher at Constructor Labs on their JavaScript Coding Bootcamps.

Camilo Brandão-de-Resende

Artificial Intelligence Specialist
Camilo is a qualified Physician (Ophthalmologist, PhD), engineer and a specialist (MSc) with 10+ years of experience in applications of statistical learning and artificial intelligence in industry and academia. He has been a researcher at the Aeronautical Institute of Technology and the Federal University of Minas Gerais, Brazil, and Carnegie Mellon University, USA.

Chris Phillips

Full-stack developer
Chris is a full-stack programmer at Dem Dx. He holds a BSc in Business and in a former career was a producer with 10+ year career in the media industry.

Jovin D'Costa

Project Manager
Jovin has 10+ years of experience with over 4 years of project and application delivery prior to joining Dem Dx. Jovin also has a BSc in Computer Systems and a PGDiploma in Network Systems Engineering from the University of Plymouth.
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Toby McAllister

Technical Support Analyst
Toby is a technical script developer. He is involved in the testing of the application and maintaining the tests. He's also heavily involved in benchmarking and stress testing the application for resilience under load.
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Sean Cregg

Clinical Relations Ambassador
Sean has 10 years experience in nursing. He has worked in cardiac and acute care, forensic nursing and also as an NMC Competence Assessor before joining DemDx. He brings clinical experience to support platform users and to develop and maintain relationships with front line clinicians.