• by Mark Walsh  @markfwal, May 31, 2013

Not long after Yahoo’s $1.1 billion acquisition of Tumblr, reports began emerging about a backlash from users of the blogging service who were less than thrilled with the Web portal’s takeover. The move has already driven thousands of the Tumblr faithful into the arms of WordPress, according to a recent TechCrunch story. But not as much has surfaced about the reaction within the ranks at Tumblr.

The departure this week of Jacob Bijani, the company’s creative director and fifth employee, however, is not a great sign for the Yahoo-Tumblr marriage. In a post on his personal blog on Tumblr, Bijani announced today was his last day at the company.

"I'm so proud of what we've all created together, and it's been a privilege to contribute to something beloved by so many," he wrote, indicating a desire to take time off and pursue “a dozen different projects planned” after five years at Tumblr.

While it’s not unusual to see key executives leave a company following an acquisition, Yahoo has taken pains to ensure that it won’t “screw up” Tumblr by allowing it to operate as a separate business and maintain its freewheeling, independent spirit. So when one of the chief creative forces behind the company exits a couple of weeks after the deal, it suggests things will not be the same, regardless of Yahoo’s stated intentions.

Tumblr didn’t respond immediately to a media inquiry on about Bijani leaving the company, first reported by Valleywag on Friday.

Separately, Ryan Sarver, director of platform at Twitter, said today he will leave the company June 28 after four years at the microblogging service. He tweeted that he has “no plans but rest.” Among other things, Sarver oversaw Twitter’s integration into iOS, boosting its exposure and helping to attract more users.