After some 30 years in the semiconductor industry, he left ARM in 2013, having led the team that developed ARM into the world’s leading semiconductor IP licensing company. By 2022, ARM chip volumes were over 30 billion units per year.
He was appointed CEO at Rolls-Royce in April 2015 with a mission to modernise, grow capacity alongside profitability and determine the future direction for a net zero world.
He left Rolls-Royce at the end of 2022, having led the teams to modernise engineering tools, processes and manufacturing facilities, and restructure to significantly enhance operational gearing.
In 2019 Rolls-Royce achieved record cash flows, before Warren steered the business successfully through the Covid-19 disruption. Under Warren’s leadership Rolls-Royce also achieved the world speed record for Electric flight and demonstrated Hydrogen combustion in an existing aero engine.
He has also served on the boards of several major engineering and technology companies since 2007, including BT Dyson and Micron, and served on several advisory boards. He is currently a non-executive at ASML, Tokamak Energy, C-Capture Ltd. and NATS Holdings Ltd. along with the advisory board for Avina Clean Hydrogen.
He is an Executive in Residence at the Saïd Business School in Oxford and an Honorary Fellow at Wadham College Oxford. He is a FIET, FRAeS, FREng, FRS, Dsit FBCS, and CBE.

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