SEVEN years ago they were in school and one was winning BT Young Scientist of the Year, now the Collison brothers are in California at the top of a company worth $100m (€75m).
Limerick natives Patrick (23) and John Collison (21) moved into the top tier of Silicon Valley entrepreneurs yesterday after their company, Stripe, gained $17m in investment from one of the world's top venture capital firms.
In total, Stripe raised $18m yesterday from investors.
Online payment system
Set up less than two years ago, Stripe is an online payments system that is taking on some of the biggest names on the web including eBay and PayPal.
The company allows businesses to sell their products online without having to get an expensive merchant's bank account to receive credit card payments.
Stripe also stores the customer details on its own system and deals with the associated compliance matters, removing another significant cost for business.
The company employs 17 people at its San Francisco offices.
The $100m price tag is "off the charts, statistically", said Silicon Valley lawyer Michael Patrick. "There must be something red hot here for Sequoia to invest at that valuation. This isn't naive money."
Last night Patrick Collison tweeted his excitement at the news.
"Huge thanks to everyone who helped us get here," he said.
They became teenage millionaires in 2008 after they, along with their partners, sold their first company Automatic for $5m.
Famously they promised to "fill the fridge" after that deal went through.
The pair are steeped in computers and technology.
Patrick took a computers course at the University of Limerick when he was just eight years old and was writing computer code at the age of 10.
He hit the headlines in 2005 when he was the overall winner at the BT Young Scientist of the Year with a new computer language.
He took A-Levels instead of the Leaving Cert to get to college as early as possible and took time out from his studies at the prestigious Massachusetts Institute of Technology to head to California with John to pursue their start up "Shuppa". Shuppa was eventually merged with Automatic.
John pursued a similar path, scoring an almost unheard of 10 A1s in the Leaving Cert and going to Harvard.
Very few Irish students are encouraged to drop out of college and go working from an early age.
In this case, however, it seems to be paying off.