Home Office chief technology officer Denise McDonagh has announced her resignation, while a new chief digital officer role is being advertised to sit alongside the replacement CTO seat.

McDonagh's career in government IT has lasted over three decades, including stints as the Department of Health's head of IT services, the deputy CIO at the Department for Environment, Food and Rural Affairs and most notably as the director of the G-Cloud programme.

She was awarded a CBE for services to government IT last year and is now planning to retire.

Last week McDonagh set out plans to replace the Home Office's two existing IT mega-deals with Fujitsu and Atos with a variety of smaller, shorter contracts with a range of suppliers, including SMEs.

As part of the technology replacement programme, dubbed 'ReSET4', the department will seek to buy services through G-Cloud wherever possible, according to McDonagh.

The Home Office has released a job advert for a CTO to replace McDonagh when she steps down, and is also advertising for a new role as chief digital officer.

The CTO will oversee 1,000 technology professionals and an annual budget of £325 million in total, providing the IT to support a department of 30,000 employees, the job advert explains - with a salary of between £85,000 and £140,000.

The successful applicant will be responsible for delivering a technology strategy, reducing dependence on legacy systems and contracts and working with the Cabinet Office, HM Treasury and other departments to exchange best practice and deploy commodity shared services.

The role of chief digital officer (CDO) is new to the Home Office. The CDO will be responsible for 300 digital professionals and a budget of £29 million a year with identical salary expectations.

Their key responsibilities will include delivering digital and data strategies and implementation plans, ensuring effective management and sharing of data, developing a data analytics capability, and overseeing the delivery of digital projects.

They will also need to support the 'ReSET4' transformation project by using agile techniques, open source solutions and open standards in the replacement of legacy systems, the advert states.

The appointment of both a CTO and a CDO is in line with guidance in the Government Digital Service's service design manual, which recommends that the dual role set up 'reflects the current state of government technology with both large legacy estates and new digital services in development'.

Speaking on a 'women in leadership' panel at the Salesforce World Tour in London in May, McDonagh said that the Home Office was committed to diversity and its technology department was 37% female - "significantly above the industry average".