Hearts are shaken because someone is about to leave again.

After having worked for nearly 25 years at Microsoft, Antoine Leblond emailed his colleagues of his departure from the company and at the same time expressed his joy and sadness for the decision.

"This coming Monday will be my 9000th day at Microsoft. It will also be my last one. After almost 25 years, I've decided it's time for me to go out and see what the non-Microsoft world has to offer. Every single day I have had here has been amazing in its own way, and I will never look back on all of these years with anything but fondness, pride in what we've accomplished together, and a real appreciation for having been lucky enough to be part of so many awesome things,"  Leblond wrote in the email. "I am sad to leave all of you, but also incredibly excited for what comes next. Thanks to each and every one of you for being a part of this amazing experience. I wish you all the best."

His departure came just days before the Build developer conference that he has usually presented in the past years.

With the company's reorganization in July last year and putting Terry Myerson on top of the Windows team; expected were organizational changes, reshuffling and employee departures in the company. It has been reported earlier that three executives might end up leaving the company, if they don't land new roles in the reorganization. Said to be nowhere in the leadership list of the company is Leblond's name, surprising many observers.

True enough, Leblond has been among the several Windows unit executives sidelined in the reorganization in September 2013. It turns out his departure only came third to earlier predicted departures. Two other longtime executives - Grant George and Jon DeVaan - left Microsoft last year after being left out as well in the reorganization. DeVaan was former corporate vice president for Windows development, while Grant was in charge of software testing for Office and Windows.

Leblond served 20 years working in the Office unit, most of the time with former Windows chief Steven Sinofsky. When Sinofsky was transferred from Office team to Windows team, Leblond spearheaded the development of Office 2010. He later followed Sinofsky to the Windows team, until he became Vice President for Windows Web Services, placing him on top of a number of Microsoft products that include the Windows 8 store.

The reorganizational changes only became visible six months after Sinofsky left the company, following the release of Windows 8.

Executive shakeups in Microsoft aren't new, however. It started last year with the replacement of CEO Steve Ballmer with Satya Nadella.