WASHINGTON (REUTERS) - The recently updated website for US President Joe Biden's White House carried an invitation for tech specialists savvy enough to find it.

Hidden in the HTML code was an invitation to join the US Digital Service, a technology unit within the White House.

"If you're reading this, we need your help building back better," the message said.

Former President Barack Obama launched the service in 2014 to recruit technologists to help revamp government services - for example by modernising Medicare's payment system or reforming hiring practices across government agencies.

Tech specialists join the Digital Service for typically one or two years.