No wonder the Cabinet Secretary in the 1980s despaired that the civil service was losing its highly skilled computer programmers. Without in-house technical nous, the poor design of many public sector information systems built by external suppliers over subsequent decades nurtured a toxic, enduring and expensive legacy.

The result is a straitjacket of tightly-coupled, proprietary silo systems built at a succession of moments in time. They embed tactical solutions based around bureaucratic processes and arbitrary organisational structures, rather then being built to meet ever-changing socio-economic, policy and operational needs. Rarely fit for purpose, and misaligned with long-standing political aspirations for “joined-up government”, these systems act like massive fat suits, weighing down public service reform and impeding the redesign and implementation of services that better meet users’ needs.

They also pollute new systems which need to “integrate” with this toxic legacy, thereby propagating out-dated processes and inefficiencies, and swallowing a disproportionate chunk of limited budgets. Such legacy lock-in corrodes the move towards a digitally-enabled reformation of our public services.

It’s not only the legacy systems ticking towards their end of life, but also some of the people with the skills to maintain them. With a series of large supplier contracts coming to an end over the next few years, there will be another opportunity to drive a long-overdue transition from old world to new. Another opportunity to rationalise data, redesign processes and diminish the role of the rusting inheritance. As better, more flexible and adaptable systems are developed around user needs and open, interoperable standards, these older systems need to be intentionally designed out, or their functionality re-platformed onto open, modular systems.

Whilst some of the old guard suppliers make glib promises about "upgrade paths”, few of the options they offer look credible. After all, who would want to implement another generation of tightly-coupled, “one size fits all” supplier-dependent systems? Far better to move towards the modular, highly scalable open architectures of successful internet companies, who operate at a speed and on a scale that puts most government requirements in the shade. It’s no coincidence that the technology bellwethers of the private sector - and indeed, the internet itself - use open source and open-standards based platforms rather than monolithic proprietary systems.

This strategic migration away from the old mission critical IT legacy systems should be an integral part of a much-needed and wider modernisation programme. The failure to resolve these legacy issues in a more timely fashion in earlier years is a classic example of poor risk management that now requires a tireless business and user focus to fix.

This is too big an opportunity to let slip: not simply to mindlessly replace one generation of technology with another, but to fundamentally redesign, re-engineer and dramatically improve the way that our public services, and the information and processes behind them, operate from front to back. The coming years provide an overdue but perfect catalyst to obsolete this toxic inheritance and replace it with the modern, open, digital infrastructure our public services deserve.