While at Yale, Ries co-founded Catalyst Recruiting, an online forum for university students to network with potential employers.

[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.

[3] Ries and Harvey did not seek a large amount of initial funding and released a minimum viable product[8] within six months.

[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.

[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.