Eric Costello

Founder

Co-founder of Slack. Frontend engineering pioneer who worked on building software in web browsers since the 1990s, inventing user experience conventions that became industry standard. Previously worked with Stewart Butterfield at Flickr.

Overview

Companies
1
Roles
Founder

Companies

1 company
Slack $1.4B
Acquired Founder

Workplace messaging and collaboration platform that transformed business communication. Originally built as an internal tool at Tiny Speck during development of the game Glitch, then pivoted to become the fastest-growing enterprise software company in history.

Founder data is compiled from company records, public announcements, and verified sources. Roles reflect current or most recent known positions.