The Royal Hospital Kilmainham in Dublin has been transformed into a tech playground for the day.
Billed as 'the ultimate tech meetup' the 404 event brings together hundreds of tech professionals, leading tech companies, award winning game designers and technology experts.
Co-founder Jackie Slattery says it is showcasing all that is new in Ireland and further afield.
She said: "There are some international speakers who are coming to share some amazing insights, we've got lightening talks with top tech companies, we have a series of installations from Irish and international technology experts aswell.
"Really it is just a massive celebration and promotion of Irish techhnology."