I am a graph theorist, algorithmicist and problem solver. I have delivered numerous polished solutions to complex and delicate problems, ranging from research software to kidney exchange programmes and resource allocation packages.I specialise in problems that can be expressed as graphs: networks of nodes with connecting edges. Such models cover a multitude of problems in areas as wide-ranging as logistics, social analyses, and medical care. These problems are often computationally hard (and often NP-hard), and I exploit my understanding of graph parameters and algorithmics to create solutions that use heuristics and parameterised algorithms for efficient searches of optimal solutions.Kidney exchange programmes are one of my main research fields. A person with end-stage kidney disease often requires a kidney transplant to improve both quality of life and life expectancy. However, finding suitable donors is complicated as there are many medical issues which can affect the viability of any transplant. A kidney exchange programme alleviates the problem of finding a donor who is both willing and medically compatible by allowing recipients to "swap" donors. The current programme in the UK, called the UK Living Kidney Sharing Scheme, has facilitated over a thousand additional kidney transplants thanks in part to the clever allocation of donor kidneys to find the greatest good.