“Technical debt” refers to the situation where important operational services are provided by out of date “legacy systems” often built on obsolete technical platforms or using programming languages that are no longer widely supported. This brings a number of challenges including very high “keeping the lights on” maintenance costs, data and cyber-security risks, and an inability to develop new functionality on technologies or systems that are no longer widely supported. The challenge is by no means limited to Government services as there is a universal temptation to invest in new feature development vs. the “worthy but dull” task of ensuring security and stability in the underlying platforms. But the situation is particularly acute across multiple Government Departments. A recent analysis by Government Security indicates that almost 50% of current Government IT spend (£2.3BN out of a total central Government spend of £4.7BN in 2019) is dedicated to “keeping the lights on” [KTLO1] activity on outdated legacy systems, with an estimated £13-22BN risk over the coming five years. The study further assesses that some Departmental services fail to meet even the minimum cyber-security standards, and the inability to extract usable data from these legacy systems has been cited by multiple interviewees as one of the greatest barriers to process transformation and innovations across Government. By way of example, the Home Office (the Department with the largest single technology spend), whilst having a clear understanding of the risks and after 3-4 years of effort, has not been able to retire any of their twelve large operational legacy systems.