The Government Digital Service (GDS) was set up in 2011 with an ambitious to-do list including bringing government services online, improving citizens' digital skills and reducing IT spending across Whitehall.
However since then GDS' work "has been too often remedial" and piecemeal, focused on gradually redesigning services and improving internal technology rather than engaging in fully-fledged transformation, Bracken (pictured) admits.
"We [the civil service] should have been doing that for the last 15 years," he says.
Instead, the policy over recent decades was to outsource IT, and thus skills, to a handful of suppliers. The unintended result: bespoke, expensive, fragmented systems across Whitehall. It's a legacy GDS is trying - with resistance from some quarters- to reverse.
However Bracken's ongoing battle against departments' inertia and exceptionalism seems to have made him more, not less, determined to succeed.
"We have a one-time chance to change this country's government, in terms of making it fit for purpose in a digital age. It's too horrible to think of the consequences if we don't," he says.
The problem, according to Bracken, is that some organisations are stuck in a 'state of learnt helplessness'.
He elaborated in a blog post: "After decades of outsourcing, they're stuck with technology they can't change. Even when they know exactly what sort of digital transformation they want to bring about, they don't know how to start."
Bracken doesn't blame legacy technology for the lack of progress, as "all technology is interim".
He concedes most departments are running on old systems that are getting increasingly expensive to maintain. They are "just not fit for purpose for what we now want to do," he says.
Instead he blames a slow-moving culture in the civil service where difficult decisions have been repeatedly delayed.
"In many cases the cost of starting again and doing it properly is now far less than the cost of maintaining and continuing to develop itI suspect like many industries, it's always easier to put off until tomorrow isn't it. But we don't have any choice anymore," Bracken says.
GDS here to do something 'big and meaningful'
What is the role of GDS in wider transformation Bracken describes the agency as "rule-setters": creating standards like the digital service manual and data standard, setting up reusable platforms and helping departments design services, write strategies and appoint staff.
However it's clear he wants GDS' role to be viewed as more strategic and long-term.
"We are not a small bit of the state that just goes around fixing the slightly-less-fixed bits. That's not what we're here to do. We're here to do something that's big and meaningful," he says.
With an election just weeks away, Bracken concedes GDS will be shaped by whoever wins power in May.
But the challenge for whichever politicians are running Whitehall is to "think about what government can and should be" in a digital era and how "citizens can interact differently with the state", he says.
One thing that desperately needs fixing is the way the government buys its technology, Bracken says.
"In technology and digital services, the whole premise of procurement is a flawed concept. We just don't procure. The word procurement is the problem - 'we buy once'. We're in a different world. We commission, we rent, we chop and change services," he says.
Bracken says many of GDS' purchases have been cheaper than even the lowest cost estimate would have been if it had been handled through formal procurement routes.
"The idea we should be procuring technology services, spending hundreds of millions of pounds for a five year future when I don't even know what we're doing next weekit's just ridiculous."
Whitehall's financial watchdog the National Audit Office has blamed a 'skills gap' in Whitehall for poor procurement practices.
But Bracken says he would like the civil service to worry more about managing its existing people better than bringing in new ones.
"The point I'd make is the thing that irritates me is not the skills we lack. It's how we're using the skills that we already have. That's the problem.
"There are skilled people in the civil service, they're just not being put to work in the right way in many caseswe've got to have multidisciplinary teams," he explains.
Finally, Bracken says he would like to see departmental siloes removed, encouraging agencies to collaborate rather than compete. After all they are all part of the same civil service, and are thus paid by and for citizens.
He jokes: "Some people ask: 'are you worried HMRC [digital team] will outstrip GDS Well, I bloody hope it does. For goodness sake, there's about 30,000 of them. There are 500 of us."