Warren is responsible for ensuring that the Digital Marketplace directly supports the UK government’s reform of digital and technology, and continues to help the public sector to buy what it needs to deliver great digital services.

His work has led to a more diverse range of digital and technology suppliers having access to the UK government’s business - there are over 5,000 suppliers available through the Digital Marketplace, and over 90% of these are small and medium-sized enterprises (SMEs).

As of the end of January 2019, total spend through the Digital Marketplace has exceeded £5.25 billion, of which almost half has been with SMEs. The Digital Marketplace offers many SMEs their first chance to supply to government, and a contract with the government can help startups get funding, which helps them scale their business.

Since January 2018, Warren has also led the Global Digital Marketplace Programme, which is a partnership between GDS and the Foreign and Commonwealth Office. It aims to help international governments make their procurement more transparent, in order to prevent corruption and to boost their digital, data and technology sectors.