Optus CEO Kelly Bayer Rosmarin resigns after series of major disasters for the company

Kelly Bayer Rosmarin has resigned as the CEO of Optus less than two weeks after a nationwide outage left 10 million customers without internet access.

The announcement was made on Monday, with Ms Bayer Rosmarin saying it was an 'appropriate time to step down'.

'On Friday I had the opportunity to appear before the Senate to expand on the cause of the network outage and how Optus recovered and responded,' she said in a statement.

'Having now had time for some personal reflection, I have come to the decision that my resignation is in the best interest of Optus going forward.

'It's been an honour and privilege to lead the team at Optus and serve our customers. I wish everyone and the company every success in the future.' 

Ms Bayer Rosmarin was only appointed to the top job on April 1, 2020. 

Her husband was seen leaving the family's $14million mansion in Vaucluse at about 12.20pm on Monday. 

He ignored journalists' questions and accelerated loudly up the road in a grey Lexus. 

A white Tesla could also be seen sitting in the garage while Ms Bayer-Rosmarin's tattooed security guards roamed the street outside the home. 

Chief financial officer Michael Venter will assume the role of interim CEO while continuing in his current position.

Former Optus business managing director Peter Kaliaropoulos will become the company's chief operating officer from Wednesday, a newly created position reporting to Mr Venter.

Ms Bayer Rosmarin's resignation follows a nationwide blackout of Optus on November 8, which left 10 million customers without access to the internet, and unable to receive calls and texts for up to 12 hours. 

In September last year, Optus experienced a data breach affecting 9.7 million current and former customers - more than a third of Australia's population.

During this month's blackout, Ms Bayer Rosmarin, 46, created a PR disaster of her own when she went missing in action for seven hours as essential services and businesses struggled to cope. 

While Ms Bayer Rosmarin was refusing to get on the front foot and communicate with furious customers, a fleet of vehicles brought in luxury items like throws, shrubbery and furniture for a photography session at her mansion. 

Even the CEO's husband, Rodney, admitted that the photo session - staged for the architect who renovated the home - was 'unfortunate timing'. 

Mr Bayer Rosmarin told Daily Mail Australia: 'They just hadn't got round to photographing it yet and it was being done today.'

Ms Bayer Rosmarin was called upon to front up to the senate inquiry at Parliament House on Friday to explain what went wrong during the network outage.

The executive was flanked by several members of security and protective services as she left the two-hour hearing through the underground exit of the building.

The CEO faced intense backlash for appearing to go missing during those crucial early hours.

'I wanted to ensure before I spoke that we could at least rule out the possibility of malicious activity,' she said.

'As soon as our cyber specialists ruled this out, I began publicly fronting the issue on behalf of my team.'

The telco earlier revealed a 'routine software upgrade' had triggered the blackout.

At around 4.05am Wednesday morning, the Optus network received changes to routing information from an international peering network following a routine software upgrade,' the statement explained.

'These routing information changes propagated through multiple layers in our network and exceeded preset safety levels on key routers which could not handle these.'

The statement said the action caused many routers to automatically disconnect from the Optus IP Core network to protect themselves.

Ms Bayer Rosmarin was born and raised in South Africa, but moved to the US when she got a scholarship at the prestigious Stanford University. 

She got a degree in industrial engineering and a master's degree in management science, winning an award for being the top graduate.

After university, she moved to California to work in Silicon Valley with both established and startup software companies.

She then worked as a management consultant with the Boston Consulting Group, and joined the Commonwealth Bank in 2004, where she held several senior roles before being appointed to the bank's executive in December 2013.

She joined Optus as deputy CEO on March 1, 2019 and exactly one year and one month later became its chief executive.