When Jeff Green and Dave Pickles founded The Trade Desk in 2009, the programmatic advertising business was still young enough that two men could reasonably claim to understand all of it. Mr. Pickles, who came from AdECN, the ad exchange that Microsoft acquired, built the technology that powered the company's ascent from a Ventura, Calif., startup to a publicly traded concern with a $1.1 billion market capitalization on its first day of trading in 2016.

Now Mr. Pickles is coming back, though in what capacity, precisely, remains somewhat unclear.

The Trade Desk announced on Thursday that Mr. Pickles, who left his role as chief technology officer and departed the board in 2023, will establish and lead something called a CTO Council. The council, the company said in a blog post, will work with engineering and product teams on "architectural direction, operational excellence, and key engineering investments," including artificial intelligence capabilities. Mr. Pickles has remained an adviser since his departure.

The timing is notable. The Trade Desk is expected to report third-quarter earnings on Nov. 9, and the company Mr. Pickles is rejoining looks rather different from the one he helped build. Revenue growth has slowed. Partners have pushed back on some products. The stock sits 91 percent below its peak.

(One imagines that "CTO Council" tested better in meetings than "the co-founder is back to help fix things.")

Mr. Green, the chief executive, was effusive in a statement. "I've missed working with him," he said. Mr. Pickles, for his part, praised the existing team's "strong foundation."

The company declined to say whether Mr. Pickles is returning full time, rejoining the board, or holding an officer title, or how his new council will divide authority with the current engineering and product leaders who have been running things since 2023.

In the technology business, as in so many others, a founder's return is rarely just a social call.

Original story published in adweek.com: "The Trade Desk Brings Back Dave Pickles Amid Growing Pains"