[1] After graduating, Ries moved to Silicon Valley in 2001 as a software engineer with There, Inc.[1] He worked with the firm until the 2003 launch of its web-based 3D Virtual World product, There.com.

[15] He was invited to speak at the Web 2.0 Expo by Tim O'Reilly, and was offered a position as entrepreneur-in-residence at Harvard Business School.

[5] Ries began to devote all of his time to the lean startup movement, and held conferences, gave talks, wrote blog entries, and served as an advisor to companies.

[10][14] In 2015, he released The Leader's Guide, a self-published version of the curriculum used in his consulting work, exclusively through Kickstarter, raising $588,903 for its publication.

[16][17] In October 2017, he released a follow-up book, The Startup Way, which shows the application of entrepreneurial principles in larger corporate environments.