In a post on the official Twitter blog, Williams explained that current Twitter COO, Dick Costolo would take his place. 

 

Williams will instead be focusing entirely on product placement.

 

“The challenges of growing an organization so quickly are numerous. Growing big is not success, in itself. Success to us means meeting our potential as a profitable company that can retain its culture and user focus while having a positive impact on the world. This is no small task. I frequently reflect on the type of focus that is required from everyone at Twitter to get us there.”

 

“This led to a realization as we launched the new Twitter. I am most satisfied while pushing product direction. Building things is my passion, and I’ve never been more excited or optimistic about what we have to build.”

 

Williams also added that the decision to bring Costolo into the company fold was a well formulated one, despite doubts other Twitter executives might have had. 

 

“When I insisted on bringing Dick into the COO role a year ago, I got a lot of questions from my board. But I knew Dick would be a strong complement to me, and this has proven to be the case. During his year at Twitter, he has been a critical leader in devising and executing our revenue efforts, while simultaneously and effectively making the trains run on time in the office.”