Speaking at CeBIT, John Wadeson, CEO of IT at Centrelink said the agency had dubbed the two Mondays following Government announcement of stimulus packages as ‘Super Mondays' internally.
Both days saw massive spikes in both online and call centre traffic.
The first announcement, which saw lump sums provided to pensioners from Monday 8th December 2008, resulted in just under a quarter of million log-ins to Centrelink's self-service portal and 200,000 phone calls to the call centre.
"The weekend before the stimulus goes out the whole system is pulled down to load the backend [in readiness] for what we call the virtual assault, where we just sink in this sea of public contact," Wadeson said.
"The first time around, we had to bring the gateways back online to do some testing. Despite all the warnings and messages on the site that the system was down, some 30,000 people still went in [in the short time it was back online for testing]."
Wadeson praised a policy of "sustained [IT system] development over a number of years" at the agency for its ability to cope with the stimulus peaks, as well as others that coincided with various Government announcements, such as payments to families affected by the Victorian bushfires or Queensland floods.
In some cases, such as the bushfires, Wadeson said Centrelink had only 24 hours to turn payments around.
"Being responsive to government is key when you're spending around two-thirds of their outlay," Wadeson said.
"It's been estimated that over $70 billion will be paid out in 2009-10."
Wadeson also revealed that of the 55 measures in the Budget relating to Centrelink, 52 involved IT.